[PATCH] Avoid invoking diff drivers during git-stash

["Shawn O. Pearce" <spearce@spearce.org>]

git-stash needs to restrict itself to plumbing when running automated
diffs as part of its operation as the user may have configured a
custom diff driver that opens an interactive UI for certain/all
files.  Doing that during scripted actions is very unfriendly to
the end-user and may cause git-stash to fail to work.

Reported by Johannes Sixt

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---

 Johannes Sixt <j.sixt@viscovery.net> wrote:
 > (1) Looking at git-stash.sh I see a few uses of 'git diff' in
 > apply_stash(). Shouldn't these use one of git-diff-{tree,index,files)? The
 > reason is that porcelain 'git diff' invokes custom diff drivers (that in my   
 > case run a UI program), whereas the plumbing does not.
 >
 > Is there a particular reason to use porcelain 'git diff'?

 Does this fix the problem?

 git-stash.sh |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/git-stash.sh b/git-stash.sh
index 7ba6162..def3163 100755
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -110,7 +110,7 @@ show_stash () {
 
 	w_commit=$(git rev-parse --verify "$s") &&
 	b_commit=$(git rev-parse --verify "$s^") &&
-	git diff $flags $b_commit $w_commit
+	git diff-tree $flags $b_commit $w_commit
 }
 
 apply_stash () {
@@ -139,7 +139,7 @@ apply_stash () {
 	unstashed_index_tree=
 	if test -n "$unstash_index" && test "$b_tree" != "$i_tree"
 	then
-		git diff --binary $s^2^..$s^2 | git apply --cached
+		git diff-tree --binary $s^2^..$s^2 | git apply --cached
 		test $? -ne 0 &&
 			die 'Conflicts in index. Try without --index.'
 		unstashed_index_tree=$(git-write-tree) ||
@@ -162,7 +162,7 @@ apply_stash () {
 			git read-tree "$unstashed_index_tree"
 		else
 			a="$TMP-added" &&
-			git diff --cached --name-only --diff-filter=A $c_tree >"$a" &&
+			git diff-index --cached --name-only --diff-filter=A $c_tree >"$a" &&
 			git read-tree --reset $c_tree &&
 			git update-index --add --stdin <"$a" ||
 				die "Cannot unstage modified files"
-- 
1.5.3.4.1249.g895be