difftool: Allow specifying unconfigured commands with --extcmd

diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
index 3621f28c7969b7848e3fbcac49647f32028f18e7..d806eaef541742f0cd3ab47c855e01749d7b6535 100755 (executable)
--- a/git-difftool--helper.sh
+++ b/git-difftool--helper.sh
@@ -19,6 +19,11 @@ should_prompt () {
        fi
 }
 
+# Indicates that --extcmd=... was specified
+use_ext_cmd () {
+       test -n "$GIT_DIFFTOOL_EXTCMD"
+}
+
 launch_merge_tool () {
        # Merged is the filename as it appears in the work tree
        # Local is the contents of a/filename
@@ -33,18 +38,29 @@ launch_merge_tool () {
        # the user with the real $MERGED name before launching $merge_tool.
        if should_prompt; then
                printf "\nViewing: '$MERGED'\n"
-               printf "Hit return to launch '%s': " "$merge_tool"
+               if use_ext_cmd; then
+                       printf "Hit return to launch '%s': " \
+                               "$GIT_DIFFTOOL_EXTCMD"
+               else
+                       printf "Hit return to launch '%s': " "$merge_tool"
+               fi
                read ans
        fi
 
-       run_merge_tool "$merge_tool"
+       if use_ext_cmd; then
+               $GIT_DIFFTOOL_EXTCMD "$LOCAL" "$REMOTE"
+       else
+               run_merge_tool "$merge_tool"
+       fi
+
 }
 
-# GIT_DIFF_TOOL indicates that --tool=... was specified
-if test -n "$GIT_DIFF_TOOL"; then
-       merge_tool="$GIT_DIFF_TOOL"
-else
-       merge_tool="$(get_merge_tool)" || exit
+if ! use_ext_cmd; then
+       if test -n "$GIT_DIFF_TOOL"; then
+               merge_tool="$GIT_DIFF_TOOL"
+       else
+               merge_tool="$(get_merge_tool)" || exit
+       fi
 fi
 
 # Launch the merge tool on each path provided by 'git diff'