Merge branch 'da/mergetools-meld-output-opt-on-macos' into maint

"git mergetool" learned to work around a wrapper MacOS X adds
around underlying meld.

* da/mergetools-meld-output-opt-on-macos:
  mergetools/meld: improve compatibiilty with Meld on macOS X

mergetools/meld

@@ -10,7 +10,7 @@ merge_cmd () {
 
 	if test "$meld_has_output_option" = true
 	then
-		"$merge_tool_path" --output "$MERGED" \
+		"$merge_tool_path" --output="$MERGED" \
 			"$LOCAL" "$BASE" "$REMOTE"
 	else
 		"$merge_tool_path" "$LOCAL" "$MERGED" "$REMOTE"