Sync with 'master'

* master:
  git-gui: don't delete source files when auto_mkindex fails

Author: gitster

git-gui/generate-tclindex.sh

@@ -23,7 +23,7 @@ then
 	: ok
 else
 	 echo >&2 "    * $TCL_PATH failed; using unoptimized loading"
-	 rm -f $@
+	 rm -f lib/tclIndex
 	 echo '# Autogenerated by git-gui Makefile' >lib/tclIndex
 	 echo >>lib/tclIndex
 	 echo "class.tcl" >>lib/tclIndex