Bug 17722 - Don't overwrite user's configurations in default config

Use "append" to avoid overwriting the user configuration.
This presumes most clients may takes care of the first value only.

conf.d/10-autohint.conf

@@ -3,6 +3,12 @@
 <fontconfig>
 <!--  Use the Autohinter --> 
   <match target="font">
-    <edit name="autohint" mode="assign"><bool>true</bool></edit>
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit name="autohint" mode="append"><bool>true</bool></edit>
   </match>
 </fontconfig>

conf.d/10-no-sub-pixel.conf

@@ -3,6 +3,12 @@
 <fontconfig>
 <!--  Enable sub-pixel rendering --> 
   <match target="font">
-    <edit name="rgba" mode="assign"><const>none</const></edit>
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit name="rgba" mode="append"><const>none</const></edit>
   </match>
 </fontconfig>

conf.d/10-sub-pixel-bgr.conf

@@ -3,6 +3,12 @@
 <fontconfig>
 <!--  Enable sub-pixel rendering --> 
   <match target="font">
-    <edit name="rgba" mode="assign"><const>bgr</const></edit>
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit name="rgba" mode="append"><const>bgr</const></edit>
   </match>
 </fontconfig>

conf.d/10-sub-pixel-rgb.conf

@@ -3,6 +3,12 @@
 <fontconfig>
 <!--  Enable sub-pixel rendering --> 
   <match target="font">
-    <edit name="rgba" mode="assign"><const>rgb</const></edit>
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit name="rgba" mode="append"><const>rgb</const></edit>
   </match>
 </fontconfig>

conf.d/10-sub-pixel-vbgr.conf

@@ -3,6 +3,12 @@
 <fontconfig>
 <!--  Enable sub-pixel rendering --> 
   <match target="font">
-    <edit name="rgba" mode="assign"><const>vbgr</const></edit>
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit name="rgba" mode="append"><const>vbgr</const></edit>
   </match>
 </fontconfig>

conf.d/10-sub-pixel-vrgb.conf

@@ -3,6 +3,12 @@
 <fontconfig>
 <!--  Enable sub-pixel rendering --> 
   <match target="font">
-    <edit name="rgba" mode="assign"><const>vrgb</const></edit>
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit name="rgba" mode="append"><const>vrgb</const></edit>
   </match>
 </fontconfig>

conf.d/10-unhinted.conf

@@ -3,6 +3,12 @@
 <fontconfig>
 <!--  Disable hinting --> 
   <match target="font">
-    <edit name="hinting" mode="assign"><bool>false</bool></edit>
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit name="hinting" mode="append"><bool>false</bool></edit>
   </match>
 </fontconfig>

conf.d/11-lcdfilter-default.conf

@@ -3,7 +3,13 @@
 <fontconfig>
 <!--  Use lcddefault as default for LCD filter -->
   <match target="font">
-    <edit mode="assign" name="lcdfilter">
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit mode="append" name="lcdfilter">
       <const>lcddefault</const>
     </edit>
   </match>

conf.d/11-lcdfilter-legacy.conf

@@ -3,7 +3,13 @@
 <fontconfig>
 <!--  Use lcdlegacy as default for LCD filter -->
   <match target="font">
-    <edit mode="assign" name="lcdfilter">
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit mode="append" name="lcdfilter">
       <const>lcdlegacy</const>
     </edit>
   </match>

conf.d/11-lcdfilter-light.conf

@@ -3,7 +3,13 @@
 <fontconfig>
 <!--  Use lcdlight as default for LCD filter -->
   <match target="font">
-    <edit mode="assign" name="lcdfilter">
+    <!--
+      This configuration is available on the major desktop environments.
+      We shouldn't overwrite it with "assign" unconditionally.
+      Most clients may picks up the first value only. so using "append"
+      may simply works to avoid it.
+    -->
+    <edit mode="append" name="lcdfilter">
       <const>lcdlight</const>
     </edit>
   </match>