Make apply-format respect git config clangformat.{binary,extensions}

Author: Ailin Nemui

apply-format

@@ -180,11 +180,16 @@ fi
 #######################################
 
 # clang-format.
-declare format="${CLANG_FORMAT:-}"
+declare format="$(git config clangformat.binary 2>/dev/null)"
 if [ -z "$format" ]; then
     format=$(type -p clang-format)
 fi
 
+declare extensions="$(git config clangformat.extensions 2>/dev/null)"
+if [ -z "$extensions" ]; then
+    extensions="c,cpp,cxx,cc,h,hpp,m,mm,js,java"
+fi
+
 if [ -z "$format" ]; then
     error_exit \
         $'You need to install clang-format.\n' \
@@ -193,7 +198,7 @@ if [ -z "$format" ]; then
         $'older distro versions, clang-format-VERSION.\n' \
         $'On Fedora it\'s available in the clang package.\n' \
         $'You can also specify your own path for clang-format by setting the\n' \
-        $'$CLANG_FORMAT environment variable.'
+        $'git config clangformat.binary config option.'
 fi
 
 # clang-format-diff.
@@ -326,9 +331,10 @@ else # Diff-only.
 
     "${git_args[@]}" "$@" \
         | "${format_diff_args[@]}" \
+            -binary="$format" \
             -p1 \
             -style="$style" \
-            -iregex="$exclusions_regex"'.*\.(c|cpp|cxx|cc|h|hpp|m|mm|js|java)' \
+            -iregex="$exclusions_regex"'.*\.('"${extensions//,/|}"')' \
             > "$patch_dest"
     # Starting with version 18, clang-format-diff exits with status 1 when there
     # are diffs, but other non-zero statuses indicate errors.