Merge branch 'cb/mergetool'

* cb/mergetool:
  Add a very basic test script for git mergetool
  Teach git mergetool to use custom commands defined at config time
  Changed an internal variable of mergetool to support custom commands
  Tidy up git mergetool's backup file behaviour

3 files changed, 162 insertions, 76 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 4027726f2..29bc51603 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -749,8 +749,10 @@ merge.summary::
 
 merge.tool::
 	Controls which merge resolution program is used by
-	linkgit:git-mergetool[1].  Valid values are: "kdiff3", "tkdiff",
-	"meld", "xxdiff", "emerge", "vimdiff", "gvimdiff", and "opendiff".
+	linkgit:git-mergetool[1].  Valid built-in values are: "kdiff3",
+	"tkdiff", "meld", "xxdiff", "emerge", "vimdiff", "gvimdiff", and
+	"opendiff".  Any other value is treated is custom merge tool
+	and there must be a corresponing mergetool.<tool>.cmd option.
 
 merge.verbosity::
 	Controls the amount of output shown by the recursive merge
@@ -777,6 +779,31 @@ mergetool.<tool>.path::
 	Override the path for the given tool.  This is useful in case
 	your tool is not in the PATH.
 
+mergetool.<tool>.cmd::
+	Specify the command to invoke the specified merge tool.  The
+	specified command is evaluated in shell with the following
+	variables available: 'BASE' is the name of a temporary file
+	containing the common base of the files to be merged, if available;
+	'LOCAL' is the name of a temporary file containing the contents of
+	the file on the current branch; 'REMOTE' is the name of a temporary
+	file containing the contents of the file from the branch being
+	merged; 'MERGED' contains the name of the file to which the merge
+	tool should write the results of a successful merge.
+
+mergetool.<tool>.trustExitCode::
+	For a custom merge command, specify whether the exit code of
+	the merge command can be used to determine whether the merge was
+	successful.  If this is not set to true then the merge target file
+	timestamp is checked and the merge assumed to have been successful
+	if the file has been updated, otherwise the user is prompted to
+	indicate the success of the merge.
+
+mergetool.keepBackup::
+	After performing a merge, the original file with conflict markers
+	can be saved as a file with a `.orig` extension.  If this variable
+	is set to `false` then this file is not preserved.  Defaults to
+	`true` (i.e. keep the backup files).
+
 pack.window::
 	The size of the window used by linkgit:git-pack-objects[1] when no
 	window size is given on the command line. Defaults to 10.
diff --git a/git-mergetool.sh b/git-mergetool.sh
index cbbb70795..5c86f6922 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -34,7 +34,7 @@ base_present () {
 
 cleanup_temp_files () {
     if test "$1" = --save-backup ; then
-	mv -- "$BACKUP" "$path.orig"
+	mv -- "$BACKUP" "$MERGED.orig"
 	rm -f -- "$LOCAL" "$REMOTE" "$BASE"
     else
 	rm -f -- "$LOCAL" "$REMOTE" "$BASE" "$BACKUP"
@@ -67,14 +67,14 @@ resolve_symlink_merge () {
 	read ans
 	case "$ans" in
 	    [lL]*)
-		git checkout-index -f --stage=2 -- "$path"
-		git add -- "$path"
+		git checkout-index -f --stage=2 -- "$MERGED"
+		git add -- "$MERGED"
 		cleanup_temp_files --save-backup
 		return
 		;;
 	    [rR]*)
-		git checkout-index -f --stage=3 -- "$path"
-		git add -- "$path"
+		git checkout-index -f --stage=3 -- "$MERGED"
+		git add -- "$MERGED"
 		cleanup_temp_files --save-backup
 		return
 		;;
@@ -95,12 +95,12 @@ resolve_deleted_merge () {
 	read ans
 	case "$ans" in
 	    [mMcC]*)
-		git add -- "$path"
+		git add -- "$MERGED"
 		cleanup_temp_files --save-backup
 		return
 		;;
 	    [dD]*)
-		git rm -- "$path" > /dev/null
+		git rm -- "$MERGED" > /dev/null
 		cleanup_temp_files
 		return
 		;;
@@ -112,11 +112,11 @@ resolve_deleted_merge () {
 }
 
 check_unchanged () {
-    if test "$path" -nt "$BACKUP" ; then
+    if test "$MERGED" -nt "$BACKUP" ; then
 	status=0;
     else
 	while true; do
-	    echo "$path seems unchanged."
+	    echo "$MERGED seems unchanged."
 	    printf "Was the merge successful? [y/n] "
 	    read answer < /dev/tty
 	    case "$answer" in
@@ -127,50 +127,38 @@ check_unchanged () {
     fi
 }
 
-save_backup () {
-    if test "$status" -eq 0; then
-	mv -- "$BACKUP" "$path.orig"
-    fi
-}
-
-remove_backup () {
-    if test "$status" -eq 0; then
-	rm "$BACKUP"
-    fi
-}
-
 merge_file () {
-    path="$1"
+    MERGED="$1"
 
-    f=`git ls-files -u -- "$path"`
+    f=`git ls-files -u -- "$MERGED"`
     if test -z "$f" ; then
-	if test ! -f "$path" ; then
-	    echo "$path: file not found"
+	if test ! -f "$MERGED" ; then
+	    echo "$MERGED: file not found"
 	else
-	    echo "$path: file does not need merging"
+	    echo "$MERGED: file does not need merging"
 	fi
 	exit 1
     fi
 
-    ext="$$$(expr "$path" : '.*\(\.[^/]*\)$')"
-    BACKUP="$path.BACKUP.$ext"
-    LOCAL="$path.LOCAL.$ext"
-    REMOTE="$path.REMOTE.$ext"
-    BASE="$path.BASE.$ext"
+    ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')"
+    BACKUP="$MERGED.BACKUP.$ext"
+    LOCAL="$MERGED.LOCAL.$ext"
+    REMOTE="$MERGED.REMOTE.$ext"
+    BASE="$MERGED.BASE.$ext"
 
-    mv -- "$path" "$BACKUP"
-    cp -- "$BACKUP" "$path"
+    mv -- "$MERGED" "$BACKUP"
+    cp -- "$BACKUP" "$MERGED"
 
-    base_mode=`git ls-files -u -- "$path" | awk '{if ($3==1) print $1;}'`
-    local_mode=`git ls-files -u -- "$path" | awk '{if ($3==2) print $1;}'`
-    remote_mode=`git ls-files -u -- "$path" | awk '{if ($3==3) print $1;}'`
+    base_mode=`git ls-files -u -- "$MERGED" | awk '{if ($3==1) print $1;}'`
+    local_mode=`git ls-files -u -- "$MERGED" | awk '{if ($3==2) print $1;}'`
+    remote_mode=`git ls-files -u -- "$MERGED" | awk '{if ($3==3) print $1;}'`
 
-    base_present   && git cat-file blob ":1:$prefix$path" >"$BASE" 2>/dev/null
-    local_present  && git cat-file blob ":2:$prefix$path" >"$LOCAL" 2>/dev/null
-    remote_present && git cat-file blob ":3:$prefix$path" >"$REMOTE" 2>/dev/null
+    base_present   && git cat-file blob ":1:$prefix$MERGED" >"$BASE" 2>/dev/null
+    local_present  && git cat-file blob ":2:$prefix$MERGED" >"$LOCAL" 2>/dev/null
+    remote_present && git cat-file blob ":3:$prefix$MERGED" >"$REMOTE" 2>/dev/null
 
     if test -z "$local_mode" -o -z "$remote_mode"; then
-	echo "Deleted merge conflict for '$path':"
+	echo "Deleted merge conflict for '$MERGED':"
 	describe_file "$local_mode" "local" "$LOCAL"
 	describe_file "$remote_mode" "remote" "$REMOTE"
 	resolve_deleted_merge
@@ -178,14 +166,14 @@ merge_file () {
     fi
 
     if is_symlink "$local_mode" || is_symlink "$remote_mode"; then
-	echo "Symbolic link merge conflict for '$path':"
+	echo "Symbolic link merge conflict for '$MERGED':"
 	describe_file "$local_mode" "local" "$LOCAL"
 	describe_file "$remote_mode" "remote" "$REMOTE"
 	resolve_symlink_merge
 	return
     fi
 
-    echo "Normal merge conflict for '$path':"
+    echo "Normal merge conflict for '$MERGED':"
     describe_file "$local_mode" "local" "$LOCAL"
     describe_file "$remote_mode" "remote" "$REMOTE"
     printf "Hit return to start merge resolution tool (%s): " "$merge_tool"
@@ -194,36 +182,32 @@ merge_file () {
     case "$merge_tool" in
 	kdiff3)
 	    if base_present ; then
-		("$merge_tool_path" --auto --L1 "$path (Base)" --L2 "$path (Local)" --L3 "$path (Remote)" \
-		    -o "$path" -- "$BASE" "$LOCAL" "$REMOTE" > /dev/null 2>&1)
+		("$merge_tool_path" --auto --L1 "$MERGED (Base)" --L2 "$MERGED (Local)" --L3 "$MERGED (Remote)" \
+		    -o "$MERGED" -- "$BASE" "$LOCAL" "$REMOTE" > /dev/null 2>&1)
 	    else
-		("$merge_tool_path" --auto --L1 "$path (Local)" --L2 "$path (Remote)" \
-		    -o "$path" -- "$LOCAL" "$REMOTE" > /dev/null 2>&1)
+		("$merge_tool_path" --auto --L1 "$MERGED (Local)" --L2 "$MERGED (Remote)" \
+		    -o "$MERGED" -- "$LOCAL" "$REMOTE" > /dev/null 2>&1)
 	    fi
 	    status=$?
-	    remove_backup
 	    ;;
 	tkdiff)
 	    if base_present ; then
-		"$merge_tool_path" -a "$BASE" -o "$path" -- "$LOCAL" "$REMOTE"
+		"$merge_tool_path" -a "$BASE" -o "$MERGED" -- "$LOCAL" "$REMOTE"
 	    else
-		"$merge_tool_path" -o "$path" -- "$LOCAL" "$REMOTE"
+		"$merge_tool_path" -o "$MERGED" -- "$LOCAL" "$REMOTE"
 	    fi
 	    status=$?
-	    save_backup
 	    ;;
 	meld|vimdiff)
 	    touch "$BACKUP"
-	    "$merge_tool_path" -- "$LOCAL" "$path" "$REMOTE"
+	    "$merge_tool_path" -- "$LOCAL" "$MERGED" "$REMOTE"
 	    check_unchanged
-	    save_backup
 	    ;;
 	gvimdiff)
-		touch "$BACKUP"
-		"$merge_tool_path" -f -- "$LOCAL" "$path" "$REMOTE"
-		check_unchanged
-		save_backup
-		;;
+	    touch "$BACKUP"
+	    "$merge_tool_path" -f -- "$LOCAL" "$MERGED" "$REMOTE"
+	    check_unchanged
+	    ;;
 	xxdiff)
 	    touch "$BACKUP"
 	    if base_present ; then
@@ -231,53 +215,68 @@ merge_file () {
 		    -R 'Accel.SaveAsMerged: "Ctrl-S"' \
 		    -R 'Accel.Search: "Ctrl+F"' \
 		    -R 'Accel.SearchForward: "Ctrl-G"' \
-		    --merged-file "$path" -- "$LOCAL" "$BASE" "$REMOTE"
+		    --merged-file "$MERGED" -- "$LOCAL" "$BASE" "$REMOTE"
 	    else
 		"$merge_tool_path" -X --show-merged-pane \
 		    -R 'Accel.SaveAsMerged: "Ctrl-S"' \
 		    -R 'Accel.Search: "Ctrl+F"' \
 		    -R 'Accel.SearchForward: "Ctrl-G"' \
-		    --merged-file "$path" -- "$LOCAL" "$REMOTE"
+		    --merged-file "$MERGED" -- "$LOCAL" "$REMOTE"
 	    fi
 	    check_unchanged
-	    save_backup
 	    ;;
 	opendiff)
 	    touch "$BACKUP"
 	    if base_present; then
-		"$merge_tool_path" "$LOCAL" "$REMOTE" -ancestor "$BASE" -merge "$path" | cat
+		"$merge_tool_path" "$LOCAL" "$REMOTE" -ancestor "$BASE" -merge "$MERGED" | cat
 	    else
-		"$merge_tool_path" "$LOCAL" "$REMOTE" -merge "$path" | cat
+		"$merge_tool_path" "$LOCAL" "$REMOTE" -merge "$MERGED" | cat
 	    fi
 	    check_unchanged
-	    save_backup
 	    ;;
 	ecmerge)
 	    touch "$BACKUP"
 	    if base_present; then
-		"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" --mode=merge3 --to="$path"
+		"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" --mode=merge3 --to="$MERGED"
 	    else
-		"$merge_tool_path" "$LOCAL" "$REMOTE" --mode=merge2 --to="$path"
+		"$merge_tool_path" "$LOCAL" "$REMOTE" --mode=merge2 --to="$MERGED"
 	    fi
 	    check_unchanged
-	    save_backup
 	    ;;
 	emerge)
 	    if base_present ; then
-		"$merge_tool_path" -f emerge-files-with-ancestor-command "$LOCAL" "$REMOTE" "$BASE" "$(basename "$path")"
+		"$merge_tool_path" -f emerge-files-with-ancestor-command "$LOCAL" "$REMOTE" "$BASE" "$(basename "$MERGED")"
 	    else
-		"$merge_tool_path" -f emerge-files-command "$LOCAL" "$REMOTE" "$(basename "$path")"
+		"$merge_tool_path" -f emerge-files-command "$LOCAL" "$REMOTE" "$(basename "$MERGED")"
 	    fi
 	    status=$?
-	    save_backup
+	    ;;
+	*)
+	    if test -n "$merge_tool_cmd"; then
+		if test "$merge_tool_trust_exit_code" = "false"; then
+		    touch "$BACKUP"
+		    ( eval $merge_tool_cmd )
+		    check_unchanged
+		else
+		    ( eval $merge_tool_cmd )
+		    status=$?
+		fi
+	    fi
 	    ;;
     esac
     if test "$status" -ne 0; then
-	echo "merge of $path failed" 1>&2
-	mv -- "$BACKUP" "$path"
+	echo "merge of $MERGED failed" 1>&2
+	mv -- "$BACKUP" "$MERGED"
 	exit 1
     fi
-    git add -- "$path"
+
+    if test "$merge_keep_backup" = "true"; then
+	mv -- "$BACKUP" "$MERGED.orig"
+    else
+	rm -- "$BACKUP"
+    fi
+
+    git add -- "$MERGED"
     cleanup_temp_files
 }
 
@@ -309,12 +308,20 @@ do
     shift
 done
 
+valid_custom_tool()
+{
+    merge_tool_cmd="$(git config mergetool.$1.cmd)"
+    test -n "$merge_tool_cmd"
+}
+
 valid_tool() {
 	case "$1" in
 		kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
 			;; # happy
 		*)
-			return 1
+			if ! valid_custom_tool "$1"; then
+				return 1
+			fi
 			;;
 	esac
 }
@@ -380,10 +387,16 @@ else
 
     init_merge_tool_path "$merge_tool"
 
-    if ! type "$merge_tool_path" > /dev/null 2>&1; then
+    merge_keep_backup="$(git config --bool merge.keepBackup || echo true)"
+
+    if test -z "$merge_tool_cmd" && ! type "$merge_tool_path" > /dev/null 2>&1; then
         echo "The merge tool $merge_tool is not available as '$merge_tool_path'"
         exit 1
     fi
+
+    if ! test -z "$merge_tool_cmd"; then
+        merge_tool_trust_exit_code="$(git config --bool mergetool.$merge_tool.trustExitCode || echo false)"
+    fi
 fi
 
 
diff --git a/t/t7610-mergetool.sh b/t/t7610-mergetool.sh
new file mode 100644
index 000000000..6b0483f3e
--- /dev/null
+++ b/t/t7610-mergetool.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+#
+# Copyright (c) 2008 Charles Bailey
+#
+
+test_description='git-mergetool
+
+Testing basic merge tool invocation'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+    echo master >file1 &&
+    git add file1 &&
+    git commit -m "added file1" &&
+    git checkout -b branch1 master &&
+    echo branch1 change >file1 &&
+    echo branch1 newfile >file2 &&
+    git add file1 file2 &&
+    git commit -m "branch1 changes" &&
+    git checkout -b branch2 master &&
+    echo branch2 change >file1 &&
+    echo branch2 newfile >file2 &&
+    git add file1 file2 &&
+    git commit -m "branch2 changes" &&
+    git checkout master &&
+    echo master updated >file1 &&
+    echo master new >file2 &&
+    git add file1 file2 &&
+    git commit -m "master updates"
+'
+
+test_expect_success 'custom mergetool' '
+    git config merge.tool mytool &&
+    git config mergetool.mytool.cmd "cat \"\$REMOTE\" >\"\$MERGED\"" &&
+    git config mergetool.mytool.trustExitCode true &&
+	git checkout branch1 &&
+    ! git merge master >/dev/null 2>&1 &&
+    ( yes "" | git mergetool file1>/dev/null 2>&1 ) &&
+    ( yes "" | git mergetool file2>/dev/null 2>&1 ) &&
+    test "$(cat file1)" = "master updated" &&
+    test "$(cat file2)" = "master new" &&
+	git commit -m "branch1 resolved with mergetool"
+'
+
+test_done