installer: install the system-wide config again

... but not completely. Parts of it should go into
C:\ProgramData\Git\config, after all. So let's split the SDK's
system-wide gitconfig as appropriate.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

.gitignore

@@ -10,10 +10,12 @@ edit-git-bash.exe
 /installer/ReleaseNotes.html
 /installer/bindimage.txt
 /installer/config.iss
+/installer/gitconfig.system
 /installer/install.log
 /installer/is-unicode.exe
 /installer/file-list.iss
 /installer/package-versions.txt
+/installer/programdata-config.template
 /mingit/exclude-list
 /mingit/root/
 /mingit/sorted-all

installer/install.iss

@@ -1839,8 +1839,10 @@ begin
                 Log('Line {#__LINE__}: Creating directory "' + ProgramData + '\Git" failed.');
             end;
         end;
-        if not FileCopy(AppDir + '\{#MINGW_BITNESS}\etc\gitconfig', ProgramData + '\Git\config', True) then begin
-            Log('Line {#__LINE__}: Creating copy "' + ProgramData + '\Git\config" failed.');
+        if not FileExists(ExpandConstant('{tmp}\programdata-config.template')) then
+            ExtractTemporaryFile('programdata-config.template');
+        if not FileCopy(ExpandConstant('{tmp}\programdata-config.template'), ProgramData + '\Git\config', True) then begin
+            Log('Line {#__LINE__}: Creating initial "' + ProgramData + '\Git\config" failed.');
         end;
     end;
     if FileExists(ProgramData+'\Git\config') then begin
@@ -1853,9 +1855,6 @@ begin
         if not Exec(AppDir+'\{#MINGW_BITNESS}\bin\git.exe','config -f config '+Cmd,
                 ProgramData+'\Git',SW_HIDE,ewWaitUntilTerminated,i) then
             LogError('Unable to configure SSL CA info: ' + Cmd);
-        if not DeleteFile(AppDir+'\{#MINGW_BITNESS}\etc\gitconfig') then begin
-            Log('Line {#__LINE__}: Deleting template config "' + AppDir + '\{#MINGW_BITNESS}\etc\gitconfig" failed.');
-        end;
     end;
 
     {

installer/release.sh

@@ -124,6 +124,50 @@ case "$LIST" in
 	;;
 esac
 
+GITCONFIG_PATH="$(echo "$LIST" | grep "^mingw$BITNESS/etc/gitconfig\$")"
+printf '' >programdata-config.template
+test -z "$GITCONFIG_PATH" || {
+	cp "/$GITCONFIG_PATH" gitconfig.system &&
+	cp "/$GITCONFIG_PATH" programdata-config.template &&
+	keys="$(git config -f gitconfig.system -l --name-only)" &&
+	for key in $keys
+	do
+		case "$key" in
+		pack.packsizelimit)
+			# remove from both, will be configured by installer
+			git config -f programdata-config.template \
+				--unset "$key" &&
+			git config -f gitconfig.system --unset "$key" ||
+			break
+			;;
+		diff.astextplain.*|filter.lfs.*|http.sslcainfo)
+			# keep in the system-wide config
+			git config -f programdata-config.template \
+				--unset "$key" ||
+			break
+			;;
+		*)
+			# move to the ProgramData template
+			git config -f gitconfig.system --unset "$key" ||
+			break
+			;;
+		esac || break
+	done &&
+	sed -i '/^\[/{:1;$d;N;/^.[^[]*$/b;s/^.*\[/[/;b1}' gitconfig.system &&
+	sed -i '/^\[/{:1;$d;N;/^.[^[]*$/b;s/^.*\[/[/;b1}' \
+		programdata-config.template ||
+	die "Could not split gitconfig"
+	LIST="$(echo "$LIST" | grep -v "^$GITCONFIG_PATH\$")"
+}
+
+printf '%s%s%s\n%s\n' \
+	'Source: {#SourcePath}\gitconfig.system; DestName: gitconfig; ' \
+	  "DestDir: {app}\\mingw$BITNESS\\etc; Flags: replacesameversion; " \
+	  'AfterInstall: DeleteFromVirtualStore' \
+	'Source: {#SourcePath}\programdata-config.template; Flags: dontcopy' \
+	>>file-list.iss ||
+die "Could not append gitconfig to file list"
+
 test -z "$LIST" ||
 echo "$LIST" |
 sed -e 's|/|\\|g' \