git am: Display some help text when patch is empty

diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index bfb01f7842e6192e0b3fbc0e3f2ab96269578289..51dd0d67ba951873df4f26b1707a1e8a713082b9 100644 (file)
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -1,3 +1,4 @@
+#!/bin/sh
 # git-mergetool--lib is a library for common merge tool functions
 diff_mode() {
        test "$TOOL_MODE" = diff
@@ -46,7 +47,7 @@ check_unchanged () {
 valid_tool () {
        case "$1" in
        kdiff3 | tkdiff | xxdiff | meld | opendiff | \
-       emerge | vimdiff | gvimdiff | ecmerge | diffuse | araxis)
+       emerge | vimdiff | gvimdiff | ecmerge | diffuse | araxis | p4merge)
                ;; # happy
        tortoisemerge)
                if ! merge_mode; then
@@ -130,6 +131,19 @@ run_merge_tool () {
                        "$merge_tool_path" "$LOCAL" "$REMOTE"
                fi
                ;;
+       p4merge)
+               if merge_mode; then
+                   touch "$BACKUP"
+                       if $base_present; then
+                               "$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" "$MERGED"
+                       else
+                               "$merge_tool_path" "$LOCAL" "$LOCAL" "$REMOTE" "$MERGED"
+                       fi
+                       check_unchanged
+               else
+                       "$merge_tool_path" "$LOCAL" "$REMOTE"
+               fi
+               ;;
        meld)
                if merge_mode; then
                        touch "$BACKUP"
@@ -323,17 +337,16 @@ guess_merge_tool () {
                else
                        tools="opendiff kdiff3 tkdiff xxdiff meld $tools"
                fi
-               tools="$tools gvimdiff diffuse ecmerge araxis"
+               tools="$tools gvimdiff diffuse ecmerge p4merge araxis"
        fi
-       if echo "${VISUAL:-$EDITOR}" | grep emacs > /dev/null 2>&1; then
-               # $EDITOR is emacs so add emerge as a candidate
-               tools="$tools emerge vimdiff"
-       elif echo "${VISUAL:-$EDITOR}" | grep vim > /dev/null 2>&1; then
-               # $EDITOR is vim so add vimdiff as a candidate
+       case "${VISUAL:-$EDITOR}" in
+       *vim*)
                tools="$tools vimdiff emerge"
-       else
+               ;;
+       *)
                tools="$tools emerge vimdiff"
-       fi
+               ;;
+       esac
        echo >&2 "merge tool candidates: $tools"
 
        # Loop over each candidate and stop when a valid merge tool is found.