mergetool: Add support for vimdiff.

Signed-off-by: James Bowes <jbowes@dangerouslyinc.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Documentation/config.txt

@@ -460,7 +460,7 @@ merge.summary::
 merge.tool::
 	Controls which merge resolution program is used by
 	gitlink:git-mergetool[l].  Valid values are: "kdiff3", "tkdiff",
-	"meld", "xxdiff", "emerge"
+	"meld", "xxdiff", "emerge", "vimdiff"
 
 merge.verbosity::
 	Controls the amount of output shown by the recursive merge

Documentation/git-mergetool.txt

@@ -25,7 +25,7 @@ OPTIONS
 -t or --tool=<tool>::
 	Use the merge resolution program specified by <tool>.
 	Valid merge tools are:
-	kdiff3, tkdiff, meld, xxdiff, and emerge.
+	kdiff3, tkdiff, meld, xxdiff, emerge, and vimdiff.
 
 	If a merge resolution program is not specified, 'git mergetool'
 	will use the configuration variable merge.tool.  If the

git-mergetool.sh

@@ -185,9 +185,9 @@ merge_file () {
 		mv -- "$BACKUP" "$path.orig"
 	    fi
 	    ;;
-	meld)
+	meld|vimdiff)
 	    touch "$BACKUP"
-	    meld -- "$LOCAL" "$path" "$REMOTE"
+	    $merge_tool -- "$LOCAL" "$path" "$REMOTE"
 	    if test "$path" -nt "$BACKUP" ; then
 		status=0;
 	    else
@@ -305,6 +305,8 @@ if test -z "$merge_tool" ; then
 	merge_tool=meld
     elif type emacs >/dev/null 2>&1; then
 	merge_tool=emerge
+    elif type vimdiff >/dev/null 2>&1; then
+	merge_tool=vimdiff
     else
 	echo "No available merge resolution programs available."
 	exit 1
@@ -312,7 +314,7 @@ if test -z "$merge_tool" ; then
 fi
 
 case "$merge_tool" in
-    kdiff3|tkdiff|meld|xxdiff)
+    kdiff3|tkdiff|meld|xxdiff|vimdiff)
 	if ! type "$merge_tool" > /dev/null 2>&1; then
 	    echo "The merge tool $merge_tool is not available"
 	    exit 1