[locale] Update documentation to mention *fixed* style

src/modules/locale/locale.conf

@@ -30,14 +30,18 @@ zone:                       "New_York"
 #
 # GeoIP needs a working Internet connection.
 # This can be managed from `welcome.conf` by adding
-# internet to the list of required conditions.
+# internet to the list of required conditions. (The welcome
+# module can also do its own GeoIP lookups, independently
+# of the lookup done here. The lookup in the welcome module
+# is used to establish language; this one is for timezone).
 #
-# The configuration
-# is in three parts: a *style*, which can be "json" or "xml"
-# depending on the kind of data returned by the service, and
-# a *url* where the data is retrieved, and an optional *selector*
-# to pick the right field out of the returned data (e.g. field
-# name in JSON or element name in XML).
+# The configuration is in three parts:
+# - a *style*, which can be "json" or "xml" depending on the
+#   kind of data returned by the service, and
+# - a *url* where the data is retrieved, and
+# - an optional *selector*
+#   to pick the right field out of the returned data (e.g. field
+#   name in JSON or element name in XML).
 #
 # The default selector (when the setting is blank) is picked to
 # work with existing JSON providers (which use "time_zone") and
@@ -45,8 +49,8 @@ zone:                       "New_York"
 #
 # If the service configured via *url* uses
 # a different attribute name (e.g. "timezone") in JSON or a
-# different element tag (e.g. "<Time_Zone>") in XML, set this
-# string to the name or tag to be used.
+# different element tag (e.g. "<Time_Zone>") in XML, set the
+# selector to the name or tag to be used.
 #
 # In JSON:
 #  - if the string contains "." characters, this is used as a
@@ -58,7 +62,10 @@ zone:                       "New_York"
 #  - all elements with the named tag (e.g. all TimeZone) elements
 #    from the document are checked; the first one with non-empty
 #    text value is used.
-#
+# Special case:
+#  - the *style* "fixed" is also supported. This ignores the data
+#    returned from the URL (but the URL must still be valid!)
+#    and just returns the value of the *selector*.
 #
 # An HTTP(S) request is made to *url*. The request should return
 # valid data in a suitable format, depending on *style*;
@@ -67,9 +74,6 @@ zone:                       "New_York"
 # does not follow the conventions of "suitable data" described
 # below, *selector* may be used to pick different data.
 #
-# Note that this example URL works, but the service is shutting
-# down in June 2018.
-#
 # Suitable JSON data looks like
 # ```
 #    {"time_zone":"America/New_York"}
@@ -84,9 +88,6 @@ zone:                       "New_York"
 #  - backslashes are removed
 #  - spaces are replaced with _
 #
-# Legacy settings "geoipStyle", "geoipUrl" and "geoipSelector"
-# in the top-level are still supported, but I'd advise against.
-#
 # To disable GeoIP checking, either comment-out the entire geoip section,
 # or set the *style* key to an unsupported format (e.g. `none`).
 # Also, note the analogous feature in src/modules/welcome/welcome.conf.
@@ -95,3 +96,12 @@ geoip:
     style:    "json"
     url:      "https://geoip.kde.org/v1/calamares"
     selector: ""  # leave blank for the default
+
+# For testing purposes, you could use *fixed* style, to see how Calamares
+# behaves in a particular zone:
+#
+# geoip:
+#     style:    "fixed"
+#     url:      "https://geoip.kde.org/v1/calamares"  # Still needs to be valid!
+#     selector: "America/Vancouver"  # this is the selected zone
+#

src/modules/welcome/welcome.conf

@@ -64,7 +64,8 @@ requirements:
 #
 # To disable GeoIP checking, either comment-out the entire geoip section,
 # or set the *style* key to an unsupported format (e.g. `none`).
-# Also, note the analogous feature in src/modules/locale/locale.conf.
+# Also, note the analogous feature in `src/modules/locale/locale.conf`,
+# which is where you will find complete documentation.
 #
 geoip:
     style:    "none"