blame.c: fix garbled error message

The helper functions prepare_final() and prepare_initial() return a
pointer to a string that is a member of an object in the revs->pending
array. This array is later rebuilt when running prepare_revision_walk()
which potentially transforms the pointer target into a bogus string. Fix
this by maintaining a copy of the original string.

Signed-off-by: Lukas Fleischer <git@cryptocrack.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/blame.c b/builtin/blame.c
index 3838be2b0274fbd72b200c2bf294e4d2842a020c..699109b4a9d7663c0f4eebb82e349e3778c2730d 100644 (file)
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -2390,7 +2390,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
        return commit;
 }
 
-static const char *prepare_final(struct scoreboard *sb)
+static char *prepare_final(struct scoreboard *sb)
 {
        int i;
        const char *final_commit_name = NULL;
@@ -2415,10 +2415,10 @@ static const char *prepare_final(struct scoreboard *sb)
                sb->final = (struct commit *) obj;
                final_commit_name = revs->pending.objects[i].name;
        }
-       return final_commit_name;
+       return xstrdup_or_null(final_commit_name);
 }
 
-static const char *prepare_initial(struct scoreboard *sb)
+static char *prepare_initial(struct scoreboard *sb)
 {
        int i;
        const char *final_commit_name = NULL;
@@ -2445,7 +2445,7 @@ static const char *prepare_initial(struct scoreboard *sb)
        }
        if (!final_commit_name)
                die("No commit to dig down to?");
-       return final_commit_name;
+       return xstrdup(final_commit_name);
 }
 
 static int blame_copy_callback(const struct option *option, const char *arg, int unset)
@@ -2489,7 +2489,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
        struct origin *o;
        struct blame_entry *ent = NULL;
        long dashdash_pos, lno;
-       const char *final_commit_name = NULL;
+       char *final_commit_name = NULL;
        enum object_type type;
 
        static struct string_list range_list;
@@ -2786,6 +2786,8 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 
        assign_blame(&sb, opt);
 
+       free(final_commit_name);
+
        if (incremental)
                return 0;