From 8e262104c25d1c2578f683109e1b373aade3a17c Mon Sep 17 00:00:00 2001
From: KN4CK3R <KN4CK3R@users.noreply.github.com>
Date: Sat, 5 Jun 2021 14:32:19 +0200
Subject: [PATCH] Add Image Diff for SVG files (#14867)

* Added type sniffer.

* Switched content detection from base to typesniffer.

* Added GuessContentType to Blob.

* Moved image info logic to client.
Added support for SVG images in diff.

* Restore old blocked svg behaviour.

* Added missing image formats.

* Execute image diff only when container is visible.

* add margin to spinner

* improve BIN tag on image diffs

* Default to render view.

* Show image diff on incomplete diff.

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Lauris BH <lauris@nix.lv>
---
 modules/avatar/avatar.go                |   5 +-
 modules/base/tool.go                    |  68 ----------
 modules/base/tool_test.go               |  92 -------------
 modules/git/blob.go                     |  13 ++
 modules/git/commit.go                   |  70 ----------
 modules/indexer/code/bleve.go           |   4 +-
 modules/indexer/code/elastic_search.go  |   4 +-
 modules/typesniffer/typesniffer.go      |  96 ++++++++++++++
 modules/typesniffer/typesniffer_test.go |  97 ++++++++++++++
 routers/repo/compare.go                 |  41 +++---
 routers/repo/download.go                |  34 ++---
 routers/repo/editor.go                  |   5 +-
 routers/repo/lfs.go                     |  17 +--
 routers/repo/setting.go                 |   4 +-
 routers/repo/view.go                    |  29 +++--
 routers/user/setting/profile.go         |   5 +-
 templates/repo/diff/box.tmpl            | 166 ++++++++++--------------
 templates/repo/diff/image_diff.tmpl     |  66 +++-------
 web_src/js/features/imagediff.js        |  74 +++++++++--
 19 files changed, 449 insertions(+), 441 deletions(-)
 create mode 100644 modules/typesniffer/typesniffer.go
 create mode 100644 modules/typesniffer/typesniffer_test.go

diff --git a/modules/avatar/avatar.go b/modules/avatar/avatar.go
index bb9c2e953b..5411a90796 100644
--- a/modules/avatar/avatar.go
+++ b/modules/avatar/avatar.go
@@ -10,8 +10,9 @@ import (
 	"image"
 	"image/color/palette"
 
-	// Enable PNG support:
-	_ "image/png"
+	_ "image/gif"  // for processing gif images
+	_ "image/jpeg" // for processing jpeg images
+	_ "image/png"  // for processing png images
 
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
diff --git a/modules/base/tool.go b/modules/base/tool.go
index c9530473e2..775fd709cf 100644
--- a/modules/base/tool.go
+++ b/modules/base/tool.go
@@ -12,10 +12,8 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
-	"net/http"
 	"os"
 	"path/filepath"
-	"regexp"
 	"runtime"
 	"strconv"
 	"strings"
@@ -30,15 +28,6 @@ import (
 	"github.com/dustin/go-humanize"
 )
 
-// Use at most this many bytes to determine Content Type.
-const sniffLen = 512
-
-// SVGMimeType MIME type of SVG images.
-const SVGMimeType = "image/svg+xml"
-
-var svgTagRegex = regexp.MustCompile(`(?si)\A\s*(?:(<!--.*?-->|<!DOCTYPE\s+svg([\s:]+.*?>|>))\s*)*<svg[\s>\/]`)
-var svgTagInXMLRegex = regexp.MustCompile(`(?si)\A<\?xml\b.*?\?>\s*(?:(<!--.*?-->|<!DOCTYPE\s+svg([\s:]+.*?>|>))\s*)*<svg[\s>\/]`)
-
 // EncodeMD5 encodes string to md5 hex value.
 func EncodeMD5(str string) string {
 	m := md5.New()
@@ -276,63 +265,6 @@ func IsLetter(ch rune) bool {
 	return 'a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z' || ch == '_' || ch >= 0x80 && unicode.IsLetter(ch)
 }
 
-// DetectContentType extends http.DetectContentType with more content types.
-func DetectContentType(data []byte) string {
-	ct := http.DetectContentType(data)
-
-	if len(data) > sniffLen {
-		data = data[:sniffLen]
-	}
-
-	if setting.UI.SVG.Enabled &&
-		((strings.Contains(ct, "text/plain") || strings.Contains(ct, "text/html")) && svgTagRegex.Match(data) ||
-			strings.Contains(ct, "text/xml") && svgTagInXMLRegex.Match(data)) {
-
-		// SVG is unsupported.  https://github.com/golang/go/issues/15888
-		return SVGMimeType
-	}
-	return ct
-}
-
-// IsRepresentableAsText returns true if file content can be represented as
-// plain text or is empty.
-func IsRepresentableAsText(data []byte) bool {
-	return IsTextFile(data) || IsSVGImageFile(data)
-}
-
-// IsTextFile returns true if file content format is plain text or empty.
-func IsTextFile(data []byte) bool {
-	if len(data) == 0 {
-		return true
-	}
-	return strings.Contains(DetectContentType(data), "text/")
-}
-
-// IsImageFile detects if data is an image format
-func IsImageFile(data []byte) bool {
-	return strings.Contains(DetectContentType(data), "image/")
-}
-
-// IsSVGImageFile detects if data is an SVG image format
-func IsSVGImageFile(data []byte) bool {
-	return strings.Contains(DetectContentType(data), SVGMimeType)
-}
-
-// IsPDFFile detects if data is a pdf format
-func IsPDFFile(data []byte) bool {
-	return strings.Contains(DetectContentType(data), "application/pdf")
-}
-
-// IsVideoFile detects if data is an video format
-func IsVideoFile(data []byte) bool {
-	return strings.Contains(DetectContentType(data), "video/")
-}
-
-// IsAudioFile detects if data is an video format
-func IsAudioFile(data []byte) bool {
-	return strings.Contains(DetectContentType(data), "audio/")
-}
-
 // EntryIcon returns the octicon class for displaying files/directories
 func EntryIcon(entry *git.TreeEntry) string {
 	switch {
diff --git a/modules/base/tool_test.go b/modules/base/tool_test.go
index fcd3ca296a..1343f5bed3 100644
--- a/modules/base/tool_test.go
+++ b/modules/base/tool_test.go
@@ -5,7 +5,6 @@
 package base
 
 import (
-	"encoding/base64"
 	"os"
 	"testing"
 	"time"
@@ -246,97 +245,6 @@ func TestIsLetter(t *testing.T) {
 	assert.False(t, IsLetter(0x93))
 }
 
-func TestDetectContentTypeLongerThanSniffLen(t *testing.T) {
-	// Pre-condition: Shorter than sniffLen detects SVG.
-	assert.Equal(t, "image/svg+xml", DetectContentType([]byte(`<!-- Comment --><svg></svg>`)))
-	// Longer than sniffLen detects something else.
-	assert.Equal(t, "text/plain; charset=utf-8", DetectContentType([]byte(`<!--
-Comment Comment Comment Comment Comment Comment Comment Comment Comment Comment
-Comment Comment Comment Comment Comment Comment Comment Comment Comment Comment
-Comment Comment Comment Comment Comment Comment Comment Comment Comment Comment
-Comment Comment Comment Comment Comment Comment Comment Comment Comment Comment
-Comment Comment Comment Comment Comment Comment Comment Comment Comment Comment
-Comment Comment Comment Comment Comment Comment Comment Comment Comment Comment
-Comment Comment Comment --><svg></svg>`)))
-}
-
-// IsRepresentableAsText
-
-func TestIsTextFile(t *testing.T) {
-	assert.True(t, IsTextFile([]byte{}))
-	assert.True(t, IsTextFile([]byte("lorem ipsum")))
-}
-
-func TestIsImageFile(t *testing.T) {
-	png, _ := base64.StdEncoding.DecodeString("iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAG0lEQVQYlWN4+vTpf3SMDTAMBYXYBLFpHgoKAeiOf0SGE9kbAAAAAElFTkSuQmCC")
-	assert.True(t, IsImageFile(png))
-	assert.False(t, IsImageFile([]byte("plain text")))
-}
-
-func TestIsSVGImageFile(t *testing.T) {
-	assert.True(t, IsSVGImageFile([]byte("<svg></svg>")))
-	assert.True(t, IsSVGImageFile([]byte("    <svg></svg>")))
-	assert.True(t, IsSVGImageFile([]byte(`<svg width="100"></svg>`)))
-	assert.True(t, IsSVGImageFile([]byte("<svg/>")))
-	assert.True(t, IsSVGImageFile([]byte(`<?xml version="1.0" encoding="UTF-8"?><svg></svg>`)))
-	assert.True(t, IsSVGImageFile([]byte(`<!-- Comment -->
-	<svg></svg>`)))
-	assert.True(t, IsSVGImageFile([]byte(`<!-- Multiple -->
-	<!-- Comments -->
-	<svg></svg>`)))
-	assert.True(t, IsSVGImageFile([]byte(`<!-- Multiline
-	Comment -->
-	<svg></svg>`)))
-	assert.True(t, IsSVGImageFile([]byte(`<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1 Basic//EN"
-	"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11-basic.dtd">
-	<svg></svg>`)))
-	assert.True(t, IsSVGImageFile([]byte(`<?xml version="1.0" encoding="UTF-8"?>
-	<!-- Comment -->
-	<svg></svg>`)))
-	assert.True(t, IsSVGImageFile([]byte(`<?xml version="1.0" encoding="UTF-8"?>
-	<!-- Multiple -->
-	<!-- Comments -->
-	<svg></svg>`)))
-	assert.True(t, IsSVGImageFile([]byte(`<?xml version="1.0" encoding="UTF-8"?>
-	<!-- Multline
-	Comment -->
-	<svg></svg>`)))
-	assert.True(t, IsSVGImageFile([]byte(`<?xml version="1.0" encoding="UTF-8"?>
-	<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
-	<!-- Multline
-	Comment -->
-	<svg></svg>`)))
-	assert.False(t, IsSVGImageFile([]byte{}))
-	assert.False(t, IsSVGImageFile([]byte("svg")))
-	assert.False(t, IsSVGImageFile([]byte("<svgfoo></svgfoo>")))
-	assert.False(t, IsSVGImageFile([]byte("text<svg></svg>")))
-	assert.False(t, IsSVGImageFile([]byte("<html><body><svg></svg></body></html>")))
-	assert.False(t, IsSVGImageFile([]byte(`<script>"<svg></svg>"</script>`)))
-	assert.False(t, IsSVGImageFile([]byte(`<!-- <svg></svg> inside comment -->
-	<foo></foo>`)))
-	assert.False(t, IsSVGImageFile([]byte(`<?xml version="1.0" encoding="UTF-8"?>
-	<!-- <svg></svg> inside comment -->
-	<foo></foo>`)))
-}
-
-func TestIsPDFFile(t *testing.T) {
-	pdf, _ := base64.StdEncoding.DecodeString("JVBERi0xLjYKJcOkw7zDtsOfCjIgMCBvYmoKPDwvTGVuZ3RoIDMgMCBSL0ZpbHRlci9GbGF0ZURlY29kZT4+CnN0cmVhbQp4nF3NPwsCMQwF8D2f4s2CNYk1baF0EHRwOwg4iJt/NsFb/PpevUE4Mjwe")
-	assert.True(t, IsPDFFile(pdf))
-	assert.False(t, IsPDFFile([]byte("plain text")))
-}
-
-func TestIsVideoFile(t *testing.T) {
-	mp4, _ := base64.StdEncoding.DecodeString("AAAAGGZ0eXBtcDQyAAAAAGlzb21tcDQyAAEI721vb3YAAABsbXZoZAAAAADaBlwX2gZcFwAAA+gA")
-	assert.True(t, IsVideoFile(mp4))
-	assert.False(t, IsVideoFile([]byte("plain text")))
-}
-
-func TestIsAudioFile(t *testing.T) {
-	mp3, _ := base64.StdEncoding.DecodeString("SUQzBAAAAAABAFRYWFgAAAASAAADbWFqb3JfYnJhbmQAbXA0MgBUWFhYAAAAEQAAA21pbm9yX3Zl")
-	assert.True(t, IsAudioFile(mp3))
-	assert.False(t, IsAudioFile([]byte("plain text")))
-}
-
 // TODO: Test EntryIcon
 
 func TestSetupGiteaRoot(t *testing.T) {
diff --git a/modules/git/blob.go b/modules/git/blob.go
index 674a6a9592..732356e5b2 100644
--- a/modules/git/blob.go
+++ b/modules/git/blob.go
@@ -10,6 +10,8 @@ import (
 	"encoding/base64"
 	"io"
 	"io/ioutil"
+
+	"code.gitea.io/gitea/modules/typesniffer"
 )
 
 // This file contains common functions between the gogit and !gogit variants for git Blobs
@@ -82,3 +84,14 @@ func (b *Blob) GetBlobContentBase64() (string, error) {
 	}
 	return string(out), nil
 }
+
+// GuessContentType guesses the content type of the blob.
+func (b *Blob) GuessContentType() (typesniffer.SniffedType, error) {
+	r, err := b.DataAsync()
+	if err != nil {
+		return typesniffer.SniffedType{}, err
+	}
+	defer r.Close()
+
+	return typesniffer.DetectContentTypeFromReader(r)
+}
diff --git a/modules/git/commit.go b/modules/git/commit.go
index 027642720d..f4d6075fe2 100644
--- a/modules/git/commit.go
+++ b/modules/git/commit.go
@@ -11,13 +11,7 @@ import (
 	"container/list"
 	"errors"
 	"fmt"
-	"image"
-	"image/color"
-	_ "image/gif"  // for processing gif images
-	_ "image/jpeg" // for processing jpeg images
-	_ "image/png"  // for processing png images
 	"io"
-	"net/http"
 	"os/exec"
 	"strconv"
 	"strings"
@@ -81,70 +75,6 @@ func (c *Commit) ParentCount() int {
 	return len(c.Parents)
 }
 
-func isImageFile(data []byte) (string, bool) {
-	contentType := http.DetectContentType(data)
-	if strings.Contains(contentType, "image/") {
-		return contentType, true
-	}
-	return contentType, false
-}
-
-// IsImageFile is a file image type
-func (c *Commit) IsImageFile(name string) bool {
-	blob, err := c.GetBlobByPath(name)
-	if err != nil {
-		return false
-	}
-
-	dataRc, err := blob.DataAsync()
-	if err != nil {
-		return false
-	}
-	defer dataRc.Close()
-	buf := make([]byte, 1024)
-	n, _ := dataRc.Read(buf)
-	buf = buf[:n]
-	_, isImage := isImageFile(buf)
-	return isImage
-}
-
-// ImageMetaData represents metadata of an image file
-type ImageMetaData struct {
-	ColorModel color.Model
-	Width      int
-	Height     int
-	ByteSize   int64
-}
-
-// ImageInfo returns information about the dimensions of an image
-func (c *Commit) ImageInfo(name string) (*ImageMetaData, error) {
-	if !c.IsImageFile(name) {
-		return nil, nil
-	}
-
-	blob, err := c.GetBlobByPath(name)
-	if err != nil {
-		return nil, err
-	}
-	reader, err := blob.DataAsync()
-	if err != nil {
-		return nil, err
-	}
-	defer reader.Close()
-	config, _, err := image.DecodeConfig(reader)
-	if err != nil {
-		return nil, err
-	}
-
-	metadata := ImageMetaData{
-		ColorModel: config.ColorModel,
-		Width:      config.Width,
-		Height:     config.Height,
-		ByteSize:   blob.Size(),
-	}
-	return &metadata, nil
-}
-
 // GetCommitByPath return the commit of relative path object.
 func (c *Commit) GetCommitByPath(relpath string) (*Commit, error) {
 	return c.repo.getCommitByPathWithID(c.ID, relpath)
diff --git a/modules/indexer/code/bleve.go b/modules/indexer/code/bleve.go
index 1d6aa51bc2..17128052f4 100644
--- a/modules/indexer/code/bleve.go
+++ b/modules/indexer/code/bleve.go
@@ -16,12 +16,12 @@ import (
 
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/analyze"
-	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/charset"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/typesniffer"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/blevesearch/bleve/v2"
@@ -211,7 +211,7 @@ func (b *BleveIndexer) addUpdate(batchWriter git.WriteCloserError, batchReader *
 	fileContents, err := ioutil.ReadAll(io.LimitReader(batchReader, size))
 	if err != nil {
 		return err
-	} else if !base.IsTextFile(fileContents) {
+	} else if !typesniffer.DetectContentType(fileContents).IsText() {
 		// FIXME: UTF-16 files will probably fail here
 		return nil
 	}
diff --git a/modules/indexer/code/elastic_search.go b/modules/indexer/code/elastic_search.go
index 982b36e8df..16d4a1821a 100644
--- a/modules/indexer/code/elastic_search.go
+++ b/modules/indexer/code/elastic_search.go
@@ -16,12 +16,12 @@ import (
 
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/analyze"
-	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/charset"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/typesniffer"
 
 	"github.com/go-enry/go-enry/v2"
 	jsoniter "github.com/json-iterator/go"
@@ -210,7 +210,7 @@ func (b *ElasticSearchIndexer) addUpdate(batchWriter git.WriteCloserError, batch
 	fileContents, err := ioutil.ReadAll(io.LimitReader(batchReader, size))
 	if err != nil {
 		return nil, err
-	} else if !base.IsTextFile(fileContents) {
+	} else if !typesniffer.DetectContentType(fileContents).IsText() {
 		// FIXME: UTF-16 files will probably fail here
 		return nil, nil
 	}
diff --git a/modules/typesniffer/typesniffer.go b/modules/typesniffer/typesniffer.go
new file mode 100644
index 0000000000..7c89f66699
--- /dev/null
+++ b/modules/typesniffer/typesniffer.go
@@ -0,0 +1,96 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package typesniffer
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"regexp"
+	"strings"
+)
+
+// Use at most this many bytes to determine Content Type.
+const sniffLen = 1024
+
+// SvgMimeType MIME type of SVG images.
+const SvgMimeType = "image/svg+xml"
+
+var svgTagRegex = regexp.MustCompile(`(?si)\A\s*(?:(<!--.*?-->|<!DOCTYPE\s+svg([\s:]+.*?>|>))\s*)*<svg[\s>\/]`)
+var svgTagInXMLRegex = regexp.MustCompile(`(?si)\A<\?xml\b.*?\?>\s*(?:(<!--.*?-->|<!DOCTYPE\s+svg([\s:]+.*?>|>))\s*)*<svg[\s>\/]`)
+
+// SniffedType contains informations about a blobs type.
+type SniffedType struct {
+	contentType string
+}
+
+// IsText etects if content format is plain text.
+func (ct SniffedType) IsText() bool {
+	return strings.Contains(ct.contentType, "text/")
+}
+
+// IsImage detects if data is an image format
+func (ct SniffedType) IsImage() bool {
+	return strings.Contains(ct.contentType, "image/")
+}
+
+// IsSvgImage detects if data is an SVG image format
+func (ct SniffedType) IsSvgImage() bool {
+	return strings.Contains(ct.contentType, SvgMimeType)
+}
+
+// IsPDF detects if data is a PDF format
+func (ct SniffedType) IsPDF() bool {
+	return strings.Contains(ct.contentType, "application/pdf")
+}
+
+// IsVideo detects if data is an video format
+func (ct SniffedType) IsVideo() bool {
+	return strings.Contains(ct.contentType, "video/")
+}
+
+// IsAudio detects if data is an video format
+func (ct SniffedType) IsAudio() bool {
+	return strings.Contains(ct.contentType, "audio/")
+}
+
+// IsRepresentableAsText returns true if file content can be represented as
+// plain text or is empty.
+func (ct SniffedType) IsRepresentableAsText() bool {
+	return ct.IsText() || ct.IsSvgImage()
+}
+
+// DetectContentType extends http.DetectContentType with more content types. Defaults to text/unknown if input is empty.
+func DetectContentType(data []byte) SniffedType {
+	if len(data) == 0 {
+		return SniffedType{"text/unknown"}
+	}
+
+	ct := http.DetectContentType(data)
+
+	if len(data) > sniffLen {
+		data = data[:sniffLen]
+	}
+
+	if (strings.Contains(ct, "text/plain") || strings.Contains(ct, "text/html")) && svgTagRegex.Match(data) ||
+		strings.Contains(ct, "text/xml") && svgTagInXMLRegex.Match(data) {
+		// SVG is unsupported. https://github.com/golang/go/issues/15888
+		ct = SvgMimeType
+	}
+
+	return SniffedType{ct}
+}
+
+// DetectContentTypeFromReader guesses the content type contained in the reader.
+func DetectContentTypeFromReader(r io.Reader) (SniffedType, error) {
+	buf := make([]byte, sniffLen)
+	n, err := r.Read(buf)
+	if err != nil && err != io.EOF {
+		return SniffedType{}, fmt.Errorf("DetectContentTypeFromReader io error: %w", err)
+	}
+	buf = buf[:n]
+
+	return DetectContentType(buf), nil
+}
diff --git a/modules/typesniffer/typesniffer_test.go b/modules/typesniffer/typesniffer_test.go
new file mode 100644
index 0000000000..a3b47c4598
--- /dev/null
+++ b/modules/typesniffer/typesniffer_test.go
@@ -0,0 +1,97 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package typesniffer
+
+import (
+	"bytes"
+	"encoding/base64"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDetectContentTypeLongerThanSniffLen(t *testing.T) {
+	// Pre-condition: Shorter than sniffLen detects SVG.
+	assert.Equal(t, "image/svg+xml", DetectContentType([]byte(`<!-- Comment --><svg></svg>`)).contentType)
+	// Longer than sniffLen detects something else.
+	assert.NotEqual(t, "image/svg+xml", DetectContentType([]byte(`<!-- `+strings.Repeat("x", sniffLen)+` --><svg></svg>`)).contentType)
+}
+
+func TestIsTextFile(t *testing.T) {
+	assert.True(t, DetectContentType([]byte{}).IsText())
+	assert.True(t, DetectContentType([]byte("lorem ipsum")).IsText())
+}
+
+func TestIsSvgImage(t *testing.T) {
+	assert.True(t, DetectContentType([]byte("<svg></svg>")).IsSvgImage())
+	assert.True(t, DetectContentType([]byte("    <svg></svg>")).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<svg width="100"></svg>`)).IsSvgImage())
+	assert.True(t, DetectContentType([]byte("<svg/>")).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?><svg></svg>`)).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<!-- Comment -->
+	<svg></svg>`)).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<!-- Multiple -->
+	<!-- Comments -->
+	<svg></svg>`)).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<!-- Multiline
+	Comment -->
+	<svg></svg>`)).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1 Basic//EN"
+	"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11-basic.dtd">
+	<svg></svg>`)).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
+	<!-- Comment -->
+	<svg></svg>`)).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
+	<!-- Multiple -->
+	<!-- Comments -->
+	<svg></svg>`)).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
+	<!-- Multline
+	Comment -->
+	<svg></svg>`)).IsSvgImage())
+	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
+	<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+	<!-- Multline
+	Comment -->
+	<svg></svg>`)).IsSvgImage())
+	assert.False(t, DetectContentType([]byte{}).IsSvgImage())
+	assert.False(t, DetectContentType([]byte("svg")).IsSvgImage())
+	assert.False(t, DetectContentType([]byte("<svgfoo></svgfoo>")).IsSvgImage())
+	assert.False(t, DetectContentType([]byte("text<svg></svg>")).IsSvgImage())
+	assert.False(t, DetectContentType([]byte("<html><body><svg></svg></body></html>")).IsSvgImage())
+	assert.False(t, DetectContentType([]byte(`<script>"<svg></svg>"</script>`)).IsSvgImage())
+	assert.False(t, DetectContentType([]byte(`<!-- <svg></svg> inside comment -->
+	<foo></foo>`)).IsSvgImage())
+	assert.False(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
+	<!-- <svg></svg> inside comment -->
+	<foo></foo>`)).IsSvgImage())
+}
+
+func TestIsPDF(t *testing.T) {
+	pdf, _ := base64.StdEncoding.DecodeString("JVBERi0xLjYKJcOkw7zDtsOfCjIgMCBvYmoKPDwvTGVuZ3RoIDMgMCBSL0ZpbHRlci9GbGF0ZURlY29kZT4+CnN0cmVhbQp4nF3NPwsCMQwF8D2f4s2CNYk1baF0EHRwOwg4iJt/NsFb/PpevUE4Mjwe")
+	assert.True(t, DetectContentType(pdf).IsPDF())
+	assert.False(t, DetectContentType([]byte("plain text")).IsPDF())
+}
+
+func TestIsVideo(t *testing.T) {
+	mp4, _ := base64.StdEncoding.DecodeString("AAAAGGZ0eXBtcDQyAAAAAGlzb21tcDQyAAEI721vb3YAAABsbXZoZAAAAADaBlwX2gZcFwAAA+gA")
+	assert.True(t, DetectContentType(mp4).IsVideo())
+	assert.False(t, DetectContentType([]byte("plain text")).IsVideo())
+}
+
+func TestIsAudio(t *testing.T) {
+	mp3, _ := base64.StdEncoding.DecodeString("SUQzBAAAAAABAFRYWFgAAAASAAADbWFqb3JfYnJhbmQAbXA0MgBUWFhYAAAAEQAAA21pbm9yX3Zl")
+	assert.True(t, DetectContentType(mp3).IsAudio())
+	assert.False(t, DetectContentType([]byte("plain text")).IsAudio())
+}
+
+func TestDetectContentTypeFromReader(t *testing.T) {
+	mp3, _ := base64.StdEncoding.DecodeString("SUQzBAAAAAABAFRYWFgAAAASAAADbWFqb3JfYnJhbmQAbXA0MgBUWFhYAAAAEQAAA21pbm9yX3Zl")
+	st, err := DetectContentTypeFromReader(bytes.NewReader(mp3))
+	assert.NoError(t, err)
+	assert.True(t, st.IsAudio())
+}
diff --git a/routers/repo/compare.go b/routers/repo/compare.go
index d02ea0b160..f53a31769d 100644
--- a/routers/repo/compare.go
+++ b/routers/repo/compare.go
@@ -37,8 +37,20 @@ func setCompareContext(ctx *context.Context, base *git.Commit, head *git.Commit,
 	ctx.Data["BaseCommit"] = base
 	ctx.Data["HeadCommit"] = head
 
+	ctx.Data["GetBlobByPathForCommit"] = func(commit *git.Commit, path string) *git.Blob {
+		if commit == nil {
+			return nil
+		}
+
+		blob, err := commit.GetBlobByPath(path)
+		if err != nil {
+			return nil
+		}
+		return blob
+	}
+
 	setPathsCompareContext(ctx, base, head, headTarget)
-	setImageCompareContext(ctx, base, head)
+	setImageCompareContext(ctx)
 	setCsvCompareContext(ctx)
 }
 
@@ -57,27 +69,18 @@ func setPathsCompareContext(ctx *context.Context, base *git.Commit, head *git.Co
 }
 
 // setImageCompareContext sets context data that is required by image compare template
-func setImageCompareContext(ctx *context.Context, base *git.Commit, head *git.Commit) {
-	ctx.Data["IsImageFileInHead"] = head.IsImageFile
-	ctx.Data["IsImageFileInBase"] = base.IsImageFile
-	ctx.Data["ImageInfoBase"] = func(name string) *git.ImageMetaData {
-		if base == nil {
-			return nil
+func setImageCompareContext(ctx *context.Context) {
+	ctx.Data["IsBlobAnImage"] = func(blob *git.Blob) bool {
+		if blob == nil {
+			return false
 		}
-		result, err := base.ImageInfo(name)
+
+		st, err := blob.GuessContentType()
 		if err != nil {
-			log.Error("ImageInfo failed: %v", err)
-			return nil
+			log.Error("GuessContentType failed: %v", err)
+			return false
 		}
-		return result
-	}
-	ctx.Data["ImageInfo"] = func(name string) *git.ImageMetaData {
-		result, err := head.ImageInfo(name)
-		if err != nil {
-			log.Error("ImageInfo failed: %v", err)
-			return nil
-		}
-		return result
+		return st.IsImage() && (setting.UI.SVG.Enabled || !st.IsSvgImage())
 	}
 }
 
diff --git a/routers/repo/download.go b/routers/repo/download.go
index 4917c233ae..bbf4684b2e 100644
--- a/routers/repo/download.go
+++ b/routers/repo/download.go
@@ -12,7 +12,6 @@ import (
 	"path/filepath"
 	"strings"
 
-	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/charset"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/git"
@@ -20,6 +19,7 @@ import (
 	"code.gitea.io/gitea/modules/lfs"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/typesniffer"
 )
 
 // ServeData download file from io.Reader
@@ -45,28 +45,32 @@ func ServeData(ctx *context.Context, name string, size int64, reader io.Reader)
 	// Google Chrome dislike commas in filenames, so let's change it to a space
 	name = strings.ReplaceAll(name, ",", " ")
 
-	if base.IsTextFile(buf) || ctx.QueryBool("render") {
+	st := typesniffer.DetectContentType(buf)
+
+	if st.IsText() || ctx.QueryBool("render") {
 		cs, err := charset.DetectEncoding(buf)
 		if err != nil {
 			log.Error("Detect raw file %s charset failed: %v, using by default utf-8", name, err)
 			cs = "utf-8"
 		}
 		ctx.Resp.Header().Set("Content-Type", "text/plain; charset="+strings.ToLower(cs))
-	} else if base.IsImageFile(buf) || base.IsPDFFile(buf) {
-		ctx.Resp.Header().Set("Content-Disposition", fmt.Sprintf(`inline; filename="%s"`, name))
-		ctx.Resp.Header().Set("Access-Control-Expose-Headers", "Content-Disposition")
-		if base.IsSVGImageFile(buf) {
-			ctx.Resp.Header().Set("Content-Security-Policy", "default-src 'none'; style-src 'unsafe-inline'; sandbox")
-			ctx.Resp.Header().Set("X-Content-Type-Options", "nosniff")
-			ctx.Resp.Header().Set("Content-Type", base.SVGMimeType)
-		}
 	} else {
-		ctx.Resp.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, name))
 		ctx.Resp.Header().Set("Access-Control-Expose-Headers", "Content-Disposition")
-		if setting.MimeTypeMap.Enabled {
-			fileExtension := strings.ToLower(filepath.Ext(name))
-			if mimetype, ok := setting.MimeTypeMap.Map[fileExtension]; ok {
-				ctx.Resp.Header().Set("Content-Type", mimetype)
+
+		if (st.IsImage() || st.IsPDF()) && (setting.UI.SVG.Enabled || !st.IsSvgImage()) {
+			ctx.Resp.Header().Set("Content-Disposition", fmt.Sprintf(`inline; filename="%s"`, name))
+			if st.IsSvgImage() {
+				ctx.Resp.Header().Set("Content-Security-Policy", "default-src 'none'; style-src 'unsafe-inline'; sandbox")
+				ctx.Resp.Header().Set("X-Content-Type-Options", "nosniff")
+				ctx.Resp.Header().Set("Content-Type", typesniffer.SvgMimeType)
+			}
+		} else {
+			ctx.Resp.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, name))
+			if setting.MimeTypeMap.Enabled {
+				fileExtension := strings.ToLower(filepath.Ext(name))
+				if mimetype, ok := setting.MimeTypeMap.Map[fileExtension]; ok {
+					ctx.Resp.Header().Set("Content-Type", mimetype)
+				}
 			}
 		}
 	}
diff --git a/routers/repo/editor.go b/routers/repo/editor.go
index 2a2c56952d..0f978c7b01 100644
--- a/routers/repo/editor.go
+++ b/routers/repo/editor.go
@@ -20,6 +20,7 @@ import (
 	"code.gitea.io/gitea/modules/repofiles"
 	repo_module "code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/typesniffer"
 	"code.gitea.io/gitea/modules/upload"
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/modules/web"
@@ -117,8 +118,8 @@ func editFile(ctx *context.Context, isNewFile bool) {
 		buf = buf[:n]
 
 		// Only some file types are editable online as text.
-		if !base.IsRepresentableAsText(buf) {
-			ctx.NotFound("base.IsRepresentableAsText", nil)
+		if !typesniffer.DetectContentType(buf).IsRepresentableAsText() {
+			ctx.NotFound("typesniffer.IsRepresentableAsText", nil)
 			return
 		}
 
diff --git a/routers/repo/lfs.go b/routers/repo/lfs.go
index c17bd2f87a..173ffb773f 100644
--- a/routers/repo/lfs.go
+++ b/routers/repo/lfs.go
@@ -25,6 +25,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/storage"
+	"code.gitea.io/gitea/modules/typesniffer"
 )
 
 const (
@@ -278,16 +279,16 @@ func LFSFileGet(ctx *context.Context) {
 	}
 	buf = buf[:n]
 
-	ctx.Data["IsTextFile"] = base.IsTextFile(buf)
-	isRepresentableAsText := base.IsRepresentableAsText(buf)
+	st := typesniffer.DetectContentType(buf)
+	ctx.Data["IsTextFile"] = st.IsText()
+	isRepresentableAsText := st.IsRepresentableAsText()
 
 	fileSize := meta.Size
 	ctx.Data["FileSize"] = meta.Size
 	ctx.Data["RawFileLink"] = fmt.Sprintf("%s%s.git/info/lfs/objects/%s/%s", setting.AppURL, ctx.Repo.Repository.FullName(), meta.Oid, "direct")
 	switch {
 	case isRepresentableAsText:
-		// This will be true for SVGs.
-		if base.IsImageFile(buf) {
+		if st.IsSvgImage() {
 			ctx.Data["IsImageFile"] = true
 		}
 
@@ -322,13 +323,13 @@ func LFSFileGet(ctx *context.Context) {
 		}
 		ctx.Data["LineNums"] = gotemplate.HTML(output.String())
 
-	case base.IsPDFFile(buf):
+	case st.IsPDF():
 		ctx.Data["IsPDFFile"] = true
-	case base.IsVideoFile(buf):
+	case st.IsVideo():
 		ctx.Data["IsVideoFile"] = true
-	case base.IsAudioFile(buf):
+	case st.IsAudio():
 		ctx.Data["IsAudioFile"] = true
-	case base.IsImageFile(buf):
+	case st.IsImage() && (setting.UI.SVG.Enabled || !st.IsSvgImage()):
 		ctx.Data["IsImageFile"] = true
 	}
 	ctx.HTML(http.StatusOK, tplSettingsLFSFile)
diff --git a/routers/repo/setting.go b/routers/repo/setting.go
index 51a0e01164..21a82491fe 100644
--- a/routers/repo/setting.go
+++ b/routers/repo/setting.go
@@ -24,6 +24,7 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/typesniffer"
 	"code.gitea.io/gitea/modules/validation"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/routers/utils"
@@ -1021,7 +1022,8 @@ func UpdateAvatarSetting(ctx *context.Context, form forms.AvatarForm) error {
 	if err != nil {
 		return fmt.Errorf("ioutil.ReadAll: %v", err)
 	}
-	if !base.IsImageFile(data) {
+	st := typesniffer.DetectContentType(data)
+	if !(st.IsImage() && !st.IsSvgImage()) {
 		return errors.New(ctx.Tr("settings.uploaded_avatar_not_a_image"))
 	}
 	if err = ctxRepo.UploadAvatar(data); err != nil {
diff --git a/routers/repo/view.go b/routers/repo/view.go
index 285cacc2df..30d7de4078 100644
--- a/routers/repo/view.go
+++ b/routers/repo/view.go
@@ -29,6 +29,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/typesniffer"
 )
 
 const (
@@ -265,7 +266,9 @@ func renderDirectory(ctx *context.Context, treeLink string) {
 		n, _ := dataRc.Read(buf)
 		buf = buf[:n]
 
-		isTextFile := base.IsTextFile(buf)
+		st := typesniffer.DetectContentType(buf)
+		isTextFile := st.IsText()
+
 		ctx.Data["FileIsText"] = isTextFile
 		ctx.Data["FileName"] = readmeFile.name
 		fileSize := int64(0)
@@ -302,7 +305,8 @@ func renderDirectory(ctx *context.Context, treeLink string) {
 					}
 					buf = buf[:n]
 
-					isTextFile = base.IsTextFile(buf)
+					st = typesniffer.DetectContentType(buf)
+					isTextFile = st.IsText()
 					ctx.Data["IsTextFile"] = isTextFile
 
 					fileSize = meta.Size
@@ -405,7 +409,9 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 	n, _ := dataRc.Read(buf)
 	buf = buf[:n]
 
-	isTextFile := base.IsTextFile(buf)
+	st := typesniffer.DetectContentType(buf)
+	isTextFile := st.IsText()
+
 	isLFSFile := false
 	isDisplayingSource := ctx.Query("display") == "source"
 	isDisplayingRendered := !isDisplayingSource
@@ -441,14 +447,16 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 				}
 				buf = buf[:n]
 
-				isTextFile = base.IsTextFile(buf)
+				st = typesniffer.DetectContentType(buf)
+				isTextFile = st.IsText()
+
 				fileSize = meta.Size
 				ctx.Data["RawFileLink"] = fmt.Sprintf("%s/media/%s/%s", ctx.Repo.RepoLink, ctx.Repo.BranchNameSubURL(), ctx.Repo.TreePath)
 			}
 		}
 	}
 
-	isRepresentableAsText := base.IsRepresentableAsText(buf)
+	isRepresentableAsText := st.IsRepresentableAsText()
 	if !isRepresentableAsText {
 		// If we can't show plain text, always try to render.
 		isDisplayingSource = false
@@ -483,8 +491,7 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 
 	switch {
 	case isRepresentableAsText:
-		// This will be true for SVGs.
-		if base.IsImageFile(buf) {
+		if st.IsSvgImage() {
 			ctx.Data["IsImageFile"] = true
 			ctx.Data["HasSourceRenderedToggle"] = true
 		}
@@ -540,13 +547,13 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 			}
 		}
 
-	case base.IsPDFFile(buf):
+	case st.IsPDF():
 		ctx.Data["IsPDFFile"] = true
-	case base.IsVideoFile(buf):
+	case st.IsVideo():
 		ctx.Data["IsVideoFile"] = true
-	case base.IsAudioFile(buf):
+	case st.IsAudio():
 		ctx.Data["IsAudioFile"] = true
-	case base.IsImageFile(buf):
+	case st.IsImage() && (setting.UI.SVG.Enabled || !st.IsSvgImage()):
 		ctx.Data["IsImageFile"] = true
 	default:
 		if fileSize >= setting.UI.MaxDisplayFileSize {
diff --git a/routers/user/setting/profile.go b/routers/user/setting/profile.go
index 8cde81f295..20042caca4 100644
--- a/routers/user/setting/profile.go
+++ b/routers/user/setting/profile.go
@@ -19,6 +19,7 @@ import (
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/typesniffer"
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/modules/web/middleware"
@@ -159,7 +160,9 @@ func UpdateAvatarSetting(ctx *context.Context, form *forms.AvatarForm, ctxUser *
 		if err != nil {
 			return fmt.Errorf("ioutil.ReadAll: %v", err)
 		}
-		if !base.IsImageFile(data) {
+
+		st := typesniffer.DetectContentType(data)
+		if !(st.IsImage() && !st.IsSvgImage()) {
 			return errors.New(ctx.Tr("settings.uploaded_avatar_not_a_image"))
 		}
 		if err = ctxUser.UploadAvatar(data); err != nil {
diff --git a/templates/repo/diff/box.tmpl b/templates/repo/diff/box.tmpl
index d8678c95c6..1ca2dcc4d8 100644
--- a/templates/repo/diff/box.tmpl
+++ b/templates/repo/diff/box.tmpl
@@ -29,10 +29,12 @@
 			{{range .Diff.Files}}
 				<li>
 					<div class="bold df ac pull-right">
-						{{if not .IsBin}}
-							{{template "repo/diff/stats" dict "file" . "root" $}}
+						{{if .IsBin}}
+							<span class="ml-1 mr-3">
+								{{$.i18n.Tr "repo.diff.bin"}}
+							</span>
 						{{else}}
-							<span>{{$.i18n.Tr "repo.diff.bin"}}</span>
+							{{template "repo/diff/stats" dict "file" . "root" $}}
 						{{end}}
 					</div>
 					<!-- todo finish all file status, now modify, add, delete and rename -->
@@ -42,108 +44,84 @@
 			{{end}}
 		</ol>
 		{{range $i, $file := .Diff.Files}}
-			{{if $file.IsIncomplete}}
-				<div class="diff-file-box diff-box file-content mt-3">
-					<h4 class="ui top attached normal header rounded">
+			{{$blobBase := call $.GetBlobByPathForCommit $.BaseCommit $file.OldName}}
+			{{$blobHead := call $.GetBlobByPathForCommit $.HeadCommit $file.Name}}
+			{{$isImage := or (call $.IsBlobAnImage $blobBase) (call $.IsBlobAnImage $blobHead)}}
+			{{$isCsv := (call $.IsCsvFile $file)}}
+			{{$showFileViewToggle := or $isImage (and (not $file.IsIncomplete) $isCsv)}}
+			<div class="diff-file-box diff-box file-content {{TabSizeClass $.Editorconfig $file.Name}} mt-3" id="diff-{{.Index}}">
+				<h4 class="diff-file-header sticky-2nd-row ui top attached normal header df ac sb">
+					<div class="df ac">
 						<a role="button" class="fold-file muted mr-2">
 							{{svg "octicon-chevron-down" 18}}
 						</a>
-						<div class="bold ui left df ac">
-							{{template "repo/diff/stats" dict "file" . "root" $}}
-						</div>
-						<span class="file mono">{{$file.Name}}</span>
-						<div class="diff-file-header-actions df ac">
-							<div class="text grey">
-								{{if $file.IsIncompleteLineTooLong}}
-									{{$.i18n.Tr "repo.diff.file_suppressed_line_too_long"}}
-								{{else}}
-									{{$.i18n.Tr "repo.diff.file_suppressed"}}
-								{{end}}
-							</div>
-							{{if $file.IsProtected}}
-								<span class="ui basic label">{{$.i18n.Tr "repo.diff.protected"}}</span>
-							{{end}}
-							{{if and (not $file.IsSubmodule) (not $.PageIsWiki)}}
-								{{if $file.IsDeleted}}
-									<a class="ui basic tiny button" rel="nofollow" href="{{EscapePound $.BeforeSourcePath}}/{{EscapePound .Name}}">{{$.i18n.Tr "repo.diff.view_file"}}</a>
-								{{else}}
-									<a class="ui basic tiny button" rel="nofollow" href="{{EscapePound $.SourcePath}}/{{EscapePound .Name}}">{{$.i18n.Tr "repo.diff.view_file"}}</a>
-								{{end}}
-							{{end}}
-						</div>
-					</h4>
-				</div>
-			{{else}}
-				<div class="diff-file-box diff-box file-content {{TabSizeClass $.Editorconfig $file.Name}} mt-3" id="diff-{{.Index}}">
-					<h4 class="diff-file-header sticky-2nd-row ui top attached normal header df ac sb">
-						<div class="df ac">
-							{{$isImage := false}}
-							{{if $file.IsDeleted}}
-								{{$isImage = (call $.IsImageFileInBase $file.Name)}}
-							{{else}}
-								{{$isImage = (call $.IsImageFileInHead $file.Name)}}
-							{{end}}
-							{{$isCsv := (call $.IsCsvFile $file)}}
-							{{$showFileViewToggle := or $isImage $isCsv}}
-							<a role="button" class="fold-file muted mr-2">
-								{{svg "octicon-chevron-down" 18}}
-							</a>
-							<div class="bold df ac">
-								{{if $file.IsBin}}
-									{{$.i18n.Tr "repo.diff.bin"}}
-								{{else}}
-									{{template "repo/diff/stats" dict "file" . "root" $}}
-								{{end}}
-							</div>
-							<span class="file mono">{{if $file.IsRenamed}}{{$file.OldName}} &rarr; {{end}}{{$file.Name}}{{if .IsLFSFile}} ({{$.i18n.Tr "repo.stored_lfs"}}){{end}}</span>
-						</div>
-						<div class="diff-file-header-actions df ac">
-							{{if $showFileViewToggle}}
-								<div class="ui compact icon buttons">
-									<span class="ui tiny basic button poping up active file-view-toggle" data-toggle-selector="#diff-source-{{$i}}" data-content="{{$.i18n.Tr "repo.file_view_source"}}" data-position="bottom center" data-variation="tiny inverted">{{svg "octicon-code"}}</span>
-									<span class="ui tiny basic button poping up file-view-toggle" data-toggle-selector="#diff-rendered-{{$i}}" data-content="{{$.i18n.Tr "repo.file_view_rendered"}}" data-position="bottom center" data-variation="tiny inverted">{{svg "octicon-file"}}</span>
-								</div>
-							{{end}}
-							{{if $file.IsProtected}}
-								<span class="ui basic label">{{$.i18n.Tr "repo.diff.protected"}}</span>
-							{{end}}
-							{{if and (not $file.IsSubmodule) (not $.PageIsWiki)}}
-								{{if $file.IsDeleted}}
-									<a class="ui basic tiny button" rel="nofollow" href="{{EscapePound $.BeforeSourcePath}}/{{EscapePound .Name}}">{{$.i18n.Tr "repo.diff.view_file"}}</a>
-								{{else}}
-									<a class="ui basic tiny button" rel="nofollow" href="{{EscapePound $.SourcePath}}/{{EscapePound .Name}}">{{$.i18n.Tr "repo.diff.view_file"}}</a>
-								{{end}}
-							{{end}}
-						</div>
-					</h4>
-					<div class="diff-file-body ui attached unstackable table segment">
-						<div id="diff-source-{{$i}}" class="file-body file-code code-diff{{if $.IsSplitStyle}} code-diff-split{{else}} code-diff-unified{{end}}">
+						<div class="bold df ac">
 							{{if $file.IsBin}}
-								<div class="diff-file-body binary" style="padding: 5px 10px;">{{$.i18n.Tr "repo.diff.bin_not_shown"}}</div>
+								<span class="ml-1 mr-3">
+									{{$.i18n.Tr "repo.diff.bin"}}
+								</span>
 							{{else}}
-								<table class="chroma">
-									{{if $.IsSplitStyle}}
-										{{template "repo/diff/section_split" dict "file" . "root" $}}
-									{{else}}
-										{{template "repo/diff/section_unified" dict "file" . "root" $}}
-									{{end}}
-								</table>
+								{{template "repo/diff/stats" dict "file" . "root" $}}
 							{{end}}
 						</div>
-						{{if or $isImage $isCsv}}
-							<div id="diff-rendered-{{$i}}" class="file-body file-code {{if $.IsSplitStyle}} code-diff-split{{else}} code-diff-unified{{end}} hide">
-								<table class="chroma w-100">
-									{{if $isImage}}
-										{{template "repo/diff/image_diff" dict "file" . "root" $}}
-									{{else}}
-										{{template "repo/diff/csv_diff" dict "file" . "root" $}}
-									{{end}}
-								</table>
+						<span class="file mono">{{if $file.IsRenamed}}{{$file.OldName}} &rarr; {{end}}{{$file.Name}}{{if .IsLFSFile}} ({{$.i18n.Tr "repo.stored_lfs"}}){{end}}</span>
+					</div>
+					<div class="diff-file-header-actions df ac">
+						{{if $showFileViewToggle}}
+							<div class="ui compact icon buttons">
+								<span class="ui tiny basic button poping up file-view-toggle" data-toggle-selector="#diff-source-{{$i}}" data-content="{{$.i18n.Tr "repo.file_view_source"}}" data-position="bottom center" data-variation="tiny inverted">{{svg "octicon-code"}}</span>
+								<span class="ui tiny basic button poping up file-view-toggle active" data-toggle-selector="#diff-rendered-{{$i}}" data-content="{{$.i18n.Tr "repo.file_view_rendered"}}" data-position="bottom center" data-variation="tiny inverted">{{svg "octicon-file"}}</span>
 							</div>
 						{{end}}
+						{{if $file.IsProtected}}
+							<span class="ui basic label">{{$.i18n.Tr "repo.diff.protected"}}</span>
+						{{end}}
+						{{if and (not $file.IsSubmodule) (not $.PageIsWiki)}}
+							{{if $file.IsDeleted}}
+								<a class="ui basic tiny button" rel="nofollow" href="{{EscapePound $.BeforeSourcePath}}/{{EscapePound .Name}}">{{$.i18n.Tr "repo.diff.view_file"}}</a>
+							{{else}}
+								<a class="ui basic tiny button" rel="nofollow" href="{{EscapePound $.SourcePath}}/{{EscapePound .Name}}">{{$.i18n.Tr "repo.diff.view_file"}}</a>
+							{{end}}
+						{{end}}
 					</div>
+				</h4>
+				<div class="diff-file-body ui attached unstackable table segment">
+					<div id="diff-source-{{$i}}" class="file-body file-code code-diff{{if $.IsSplitStyle}} code-diff-split{{else}} code-diff-unified{{end}}{{if $showFileViewToggle}} hide{{end}}">
+						{{if or $file.IsIncomplete $file.IsBin}}
+							<div class="diff-file-body binary" style="padding: 5px 10px;">
+								{{if $file.IsIncomplete}}
+									{{if $file.IsIncompleteLineTooLong}}
+										{{$.i18n.Tr "repo.diff.file_suppressed_line_too_long"}}
+									{{else}}
+										{{$.i18n.Tr "repo.diff.file_suppressed"}}
+									{{end}}
+								{{else}}
+									{{$.i18n.Tr "repo.diff.bin_not_shown"}}
+								{{end}}
+							</div>
+						{{else}}
+							<table class="chroma">
+								{{if $.IsSplitStyle}}
+									{{template "repo/diff/section_split" dict "file" . "root" $}}
+								{{else}}
+									{{template "repo/diff/section_unified" dict "file" . "root" $}}
+								{{end}}
+							</table>
+						{{end}}
+					</div>
+					{{if $showFileViewToggle}}
+						<div id="diff-rendered-{{$i}}" class="file-body file-code {{if $.IsSplitStyle}} code-diff-split{{else}} code-diff-unified{{end}}">
+							<table class="chroma w-100">
+								{{if $isImage}}
+									{{template "repo/diff/image_diff" dict "file" . "root" $ "blobBase" $blobBase "blobHead" $blobHead}}
+								{{else}}
+									{{template "repo/diff/csv_diff" dict "file" . "root" $}}
+								{{end}}
+							</table>
+						</div>
+					{{end}}
 				</div>
-			{{end}}
+			</div>
 		{{end}}
 
 		{{if .Diff.IsIncomplete}}
diff --git a/templates/repo/diff/image_diff.tmpl b/templates/repo/diff/image_diff.tmpl
index 91092c412f..33fa8c9e2c 100644
--- a/templates/repo/diff/image_diff.tmpl
+++ b/templates/repo/diff/image_diff.tmpl
@@ -1,15 +1,13 @@
 {{ $imagePathOld := printf "%s/%s" .root.BeforeRawPath (EscapePound .file.OldName)  }}
 {{ $imagePathNew := printf "%s/%s" .root.RawPath (EscapePound .file.Name)  }}
-{{ $imageInfoBase := (call .root.ImageInfoBase .file.OldName) }}
-{{ $imageInfoHead := (call .root.ImageInfo .file.Name) }}
-{{if or $imageInfoBase $imageInfoHead}}
+{{if or .blobBase .blobHead}}
 <tr>
 	<td colspan="2">
 		<div class="image-diff" data-path-before="{{$imagePathOld}}" data-path-after="{{$imagePathNew}}">
 			<div class="ui secondary pointing tabular top attached borderless menu stackable new-menu">
 				<div class="new-menu-inner">
 					<a class="item active" data-tab="diff-side-by-side">{{.root.i18n.Tr "repo.diff.image.side_by_side"}}</a>
-					{{if and $imageInfoBase $imageInfoHead}}
+					{{if and .blobBase .blobHead}}
 					<a class="item" data-tab="diff-swipe">{{.root.i18n.Tr "repo.diff.image.swipe"}}</a>
 					<a class="item" data-tab="diff-overlay">{{.root.i18n.Tr "repo.diff.image.overlay"}}</a>
 					{{end}}
@@ -18,63 +16,39 @@
 			<div class="hide">
 				<div class="ui bottom attached tab image-diff-container active" data-tab="diff-side-by-side">
 					<div class="diff-side-by-side">
-						{{if $imageInfoBase }}
+						{{if .blobBase }}
 						<span class="side">
 							<p class="side-header">{{.root.i18n.Tr "repo.diff.file_before"}}</p>
 							<span class="before-container"><img class="image-before" /></span>
 							<p>
-								{{ $classWidth := "" }}
-								{{ $classHeight := "" }}
-								{{ $classByteSize := "" }}
-								{{if $imageInfoHead}}
-									{{if not (eq $imageInfoBase.Width $imageInfoHead.Width)}}
-										{{ $classWidth = "red" }}
-									{{end}}
-									{{if not (eq $imageInfoBase.Height $imageInfoHead.Height)}}
-										{{ $classHeight = "red" }}
-									{{end}}
-									{{if not (eq $imageInfoBase.ByteSize $imageInfoHead.ByteSize)}}
-										{{ $classByteSize = "red" }}
-									{{end}}
-								{{end}}
-								{{.root.i18n.Tr "repo.diff.file_image_width"}}: <span class="text {{$classWidth}}">{{$imageInfoBase.Width}}</span>
-								&nbsp;|&nbsp;
-								{{.root.i18n.Tr "repo.diff.file_image_height"}}: <span class="text {{$classHeight}}">{{$imageInfoBase.Height}}</span>
-								&nbsp;|&nbsp;
-								{{.root.i18n.Tr "repo.diff.file_byte_size"}}: <span class="text {{$classByteSize}}">{{FileSize $imageInfoBase.ByteSize}}</span>
+								<span class="bounds-info-before">
+									{{.root.i18n.Tr "repo.diff.file_image_width"}}: <span class="text bounds-info-width"></span>
+									&nbsp;|&nbsp;
+									{{.root.i18n.Tr "repo.diff.file_image_height"}}: <span class="text bounds-info-height"></span>
+									&nbsp;|&nbsp;
+								</span>
+								{{.root.i18n.Tr "repo.diff.file_byte_size"}}: <span class="text">{{FileSize .blobBase.Size}}</span>
 							</p>
 						</span>
 						{{end}}
-						{{if $imageInfoHead }}
+						{{if .blobHead }}
 						<span class="side">
 							<p class="side-header">{{.root.i18n.Tr "repo.diff.file_after"}}</p>
 							<span class="after-container"><img class="image-after" /></span>
 							<p>
-								{{ $classWidth := "" }}
-								{{ $classHeight := "" }}
-								{{ $classByteSize := "" }}
-								{{if $imageInfoBase}}
-									{{if not (eq $imageInfoBase.Width $imageInfoHead.Width)}}
-										{{ $classWidth = "green" }}
-									{{end}}
-									{{if not (eq $imageInfoBase.Height $imageInfoHead.Height)}}
-										{{ $classHeight = "green" }}
-									{{end}}
-									{{if not (eq $imageInfoBase.ByteSize $imageInfoHead.ByteSize)}}
-										{{ $classByteSize = "green" }}
-									{{end}}
-								{{end}}
-								{{.root.i18n.Tr "repo.diff.file_image_width"}}: <span class="text {{$classWidth}}">{{$imageInfoHead.Width}}</span>
-								&nbsp;|&nbsp;
-								{{.root.i18n.Tr "repo.diff.file_image_height"}}: <span class="text {{$classHeight}}">{{$imageInfoHead.Height}}</span>
-								&nbsp;|&nbsp;
-								{{.root.i18n.Tr "repo.diff.file_byte_size"}}: <span class="text {{$classByteSize}}">{{FileSize $imageInfoHead.ByteSize}}</span>
+								<span class="bounds-info-after">
+									{{.root.i18n.Tr "repo.diff.file_image_width"}}: <span class="text bounds-info-width"></span>
+									&nbsp;|&nbsp;
+									{{.root.i18n.Tr "repo.diff.file_image_height"}}: <span class="text bounds-info-height"></span>
+									&nbsp;|&nbsp;
+								</span>
+								{{.root.i18n.Tr "repo.diff.file_byte_size"}}: <span class="text">{{FileSize .blobHead.Size}}</span>
 							</p>
 						</span>
 						{{end}}
 					</div>
 				</div>
-				{{if and $imageInfoBase $imageInfoHead}}
+				{{if and .blobBase .blobHead}}
 				<div class="ui bottom attached tab image-diff-container" data-tab="diff-swipe">
 					<div class="diff-swipe">
 						<div class="swipe-frame">
@@ -102,7 +76,7 @@
 				</div>
 				{{end}}
 			</div>
-			<div class="ui active centered inline loader"></div>
+			<div class="ui active centered inline loader mb-4"></div>
 		</div>
 	</td>
 </tr>
diff --git a/web_src/js/features/imagediff.js b/web_src/js/features/imagediff.js
index ce7ce8d2af..67e9548596 100644
--- a/web_src/js/features/imagediff.js
+++ b/web_src/js/features/imagediff.js
@@ -1,3 +1,34 @@
+function getDefaultSvgBoundsIfUndefined(svgXml, src) {
+  const DefaultSize = 300;
+  const MaxSize = 99999;
+
+  const svg = svgXml.rootElement;
+
+  const width = svg.width.baseVal;
+  const height = svg.height.baseVal;
+  if (width.unitType === SVGLength.SVG_LENGTHTYPE_PERCENTAGE || height.unitType === SVGLength.SVG_LENGTHTYPE_PERCENTAGE) {
+    const img = new Image();
+    img.src = src;
+    if (img.width > 1 && img.width < MaxSize && img.height > 1 && img.height < MaxSize) {
+      return {
+        width: img.width,
+        height: img.height
+      };
+    }
+    if (svg.hasAttribute('viewBox')) {
+      const viewBox = svg.viewBox.baseVal;
+      return {
+        width: DefaultSize,
+        height: DefaultSize * viewBox.width / viewBox.height
+      };
+    }
+    return {
+      width: DefaultSize,
+      height: DefaultSize
+    };
+  }
+}
+
 export default async function initImageDiff() {
   function createContext(image1, image2) {
     const size1 = {
@@ -30,34 +61,50 @@ export default async function initImageDiff() {
 
   $('.image-diff').each(function() {
     const $container = $(this);
+
+    const diffContainerWidth = $container.width() - 300;
     const pathAfter = $container.data('path-after');
     const pathBefore = $container.data('path-before');
 
     const imageInfos = [{
       loaded: false,
       path: pathAfter,
-      $image: $container.find('img.image-after')
+      $image: $container.find('img.image-after'),
+      $boundsInfo: $container.find('.bounds-info-after')
     }, {
       loaded: false,
       path: pathBefore,
-      $image: $container.find('img.image-before')
+      $image: $container.find('img.image-before'),
+      $boundsInfo: $container.find('.bounds-info-before')
     }];
 
     for (const info of imageInfos) {
       if (info.$image.length > 0) {
-        info.$image.on('load', () => {
-          info.loaded = true;
-          setReadyIfLoaded();
+        $.ajax({
+          url: info.path,
+          success: (data, _, jqXHR) => {
+            info.$image.on('load', () => {
+              info.loaded = true;
+              setReadyIfLoaded();
+            });
+            info.$image.attr('src', info.path);
+
+            if (jqXHR.getResponseHeader('Content-Type') === 'image/svg+xml') {
+              const bounds = getDefaultSvgBoundsIfUndefined(data, info.path);
+              if (bounds) {
+                info.$image.attr('width', bounds.width);
+                info.$image.attr('height', bounds.height);
+                info.$boundsInfo.hide();
+              }
+            }
+          }
         });
-        info.$image.attr('src', info.path);
       } else {
         info.loaded = true;
         setReadyIfLoaded();
       }
     }
 
-    const diffContainerWidth = $container.width() - 300;
-
     function setReadyIfLoaded() {
       if (imageInfos[0].loaded && imageInfos[1].loaded) {
         initViews(imageInfos[0].$image, imageInfos[1].$image);
@@ -81,6 +128,17 @@ export default async function initImageDiff() {
         factor = (diffContainerWidth - 24) / 2 / sizes.max.width;
       }
 
+      const widthChanged = sizes.image1.length !== 0 && sizes.image2.length !== 0 && sizes.image1[0].naturalWidth !== sizes.image2[0].naturalWidth;
+      const heightChanged = sizes.image1.length !== 0 && sizes.image2.length !== 0 && sizes.image1[0].naturalHeight !== sizes.image2[0].naturalHeight;
+      if (sizes.image1.length !== 0) {
+        $container.find('.bounds-info-after .bounds-info-width').text(`${sizes.image1[0].naturalWidth}px`).addClass(widthChanged ? 'green' : '');
+        $container.find('.bounds-info-after .bounds-info-height').text(`${sizes.image1[0].naturalHeight}px`).addClass(heightChanged ? 'green' : '');
+      }
+      if (sizes.image2.length !== 0) {
+        $container.find('.bounds-info-before .bounds-info-width').text(`${sizes.image2[0].naturalWidth}px`).addClass(widthChanged ? 'red' : '');
+        $container.find('.bounds-info-before .bounds-info-height').text(`${sizes.image2[0].naturalHeight}px`).addClass(heightChanged ? 'red' : '');
+      }
+
       sizes.image1.css({
         width: sizes.size1.width * factor,
         height: sizes.size1.height * factor