merge: keep stash[] a local variable

A stash is created by save_state() and used by restore_state(). Pass
SHA-1 explicitly for clarity and keep stash[] to cmd_merge().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/merge.c b/builtin/merge.c
index 325891edb610945d01899b102993202af279bf3f..a068660d0989a803a871aa6d820e0cc347bbf586 100644 (file)
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -50,7 +50,7 @@ static int fast_forward_only;
 static int allow_trivial = 1, have_message;
 static struct strbuf merge_msg;
 static struct commit_list *remoteheads;
-static unsigned char head[20], stash[20];
+static unsigned char head[20];
 static struct strategy **use_strategies;
 static size_t use_strategies_nr, use_strategies_alloc;
 static const char **xopts;
@@ -217,7 +217,7 @@ static void drop_save(void)
        unlink(git_path("MERGE_MODE"));
 }
 
-static void save_state(void)
+static int save_state(unsigned char *stash)
 {
        int len;
        struct child_process cp;
@@ -236,11 +236,12 @@ static void save_state(void)
 
        if (finish_command(&cp) || len < 0)
                die(_("stash failed"));
-       else if (!len)
-               return;
+       else if (!len)          /* no changes */
+               return -1;
        strbuf_setlen(&buffer, buffer.len-1);
        if (get_sha1(buffer.buf, stash))
                die(_("not a valid object: %s"), buffer.buf);
+       return 0;
 }
 
 static void read_empty(unsigned const char *sha1, int verbose)
@@ -278,7 +279,7 @@ static void reset_hard(unsigned const char *sha1, int verbose)
                die(_("read-tree failed"));
 }
 
-static void restore_state(void)
+static void restore_state(const unsigned char *stash)
 {
        struct strbuf sb = STRBUF_INIT;
        const char *args[] = { "stash", "apply", NULL, NULL };
@@ -1010,6 +1011,7 @@ static int setup_with_upstream(const char ***argv)
 int cmd_merge(int argc, const char **argv, const char *prefix)
 {
        unsigned char result_tree[20];
+       unsigned char stash[20];
        struct strbuf buf = STRBUF_INIT;
        const char *head_arg;
        int flag, head_invalid = 0, i;
@@ -1320,21 +1322,18 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
         * sync with the head commit.  The strategies are responsible
         * to ensure this.
         */
-       if (use_strategies_nr != 1) {
-               /*
-                * Stash away the local changes so that we can try more
-                * than one.
-                */
-               save_state();
-       } else {
-               memcpy(stash, null_sha1, 20);
-       }
+       if (use_strategies_nr == 1 ||
+           /*
+            * Stash away the local changes so that we can try more than one.
+            */
+           save_state(stash))
+               hashcpy(stash, null_sha1);
 
        for (i = 0; i < use_strategies_nr; i++) {
                int ret;
                if (i) {
                        printf(_("Rewinding the tree to pristine...\n"));
-                       restore_state();
+                       restore_state(stash);
                }
                if (use_strategies_nr != 1)
                        printf(_("Trying merge strategy %s...\n"),
@@ -1395,7 +1394,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
         * it up.
         */
        if (!best_strategy) {
-               restore_state();
+               restore_state(stash);
                if (use_strategies_nr > 1)
                        fprintf(stderr,
                                _("No merge strategy handled the merge.\n"));
@@ -1407,7 +1406,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                ; /* We already have its result in the working tree. */
        else {
                printf(_("Rewinding the tree to pristine...\n"));
-               restore_state();
+               restore_state(stash);
                printf(_("Using the %s to prepare resolving by hand.\n"),
                        best_strategy);
                try_merge_strategy(best_strategy, common, head_arg);