refs: ref entry with NULL sha1 is can be a dangling symref

diff --git a/builtin-reset.c b/builtin-reset.c
index a0321694c5c3d5798d28f8fe14493652e0dd0054..7e7ebabaa865ebd749502774638efe7b6d26bec1 100644 (file)
--- a/builtin-reset.c
+++ b/builtin-reset.c
@@ -20,11 +20,14 @@
 #include "parse-options.h"
 
 static const char * const git_reset_usage[] = {
-       "git-reset [--mixed | --soft | --hard] [-q] [<commit>]",
-       "git-reset [--mixed] <commit> [--] <paths>...",
+       "git reset [--mixed | --soft | --hard | --merge] [-q] [<commit>]",
+       "git reset [--mixed] <commit> [--] <paths>...",
        NULL
 };
 
+enum reset_type { MIXED, SOFT, HARD, MERGE, NONE };
+static const char *reset_type_names[] = { "mixed", "soft", "hard", "merge", NULL };
+
 static char *args_to_str(const char **argv)
 {
        char *buf = NULL;
@@ -49,7 +52,7 @@ static inline int is_merge(void)
        return !access(git_path("MERGE_HEAD"), F_OK);
 }
 
-static int reset_index_file(const unsigned char *sha1, int is_hard_reset, int quiet)
+static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
 {
        int i = 0;
        const char *args[6];
@@ -57,9 +60,17 @@ static int reset_index_file(const unsigned char *sha1, int is_hard_reset, int qu
        args[i++] = "read-tree";
        if (!quiet)
                args[i++] = "-v";
-       args[i++] = "--reset";
-       if (is_hard_reset)
+       switch (reset_type) {
+       case MERGE:
+               args[i++] = "-u";
+               args[i++] = "-m";
+               break;
+       case HARD:
                args[i++] = "-u";
+               /* fallthrough */
+       default:
+               args[i++] = "--reset";
+       }
        args[i++] = sha1_to_hex(sha1);
        args[i] = NULL;
 
@@ -85,7 +96,7 @@ static void print_new_head_line(struct commit *commit)
                printf("\n");
 }
 
-static int update_index_refresh(int fd, struct lock_file *index_lock)
+static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
 {
        int result;
 
@@ -96,7 +107,8 @@ static int update_index_refresh(int fd, struct lock_file *index_lock)
 
        if (read_cache() < 0)
                return error("Could not read index");
-       result = refresh_cache(0) ? 1 : 0;
+
+       result = refresh_cache(flags) ? 1 : 0;
        if (write_cache(fd, active_cache, active_nr) ||
                        commit_locked_index(index_lock))
                return error ("Could not refresh index");
@@ -120,6 +132,9 @@ static void update_index_from_diff(struct diff_queue_struct *q,
                        struct cache_entry *ce;
                        ce = make_cache_entry(one->mode, one->sha1, one->path,
                                0, 0);
+                       if (!ce)
+                               die("make_cache_entry failed for path '%s'",
+                                   one->path);
                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
                                ADD_CACHE_OK_TO_REPLACE);
                } else
@@ -128,7 +143,7 @@ static void update_index_from_diff(struct diff_queue_struct *q,
 }
 
 static int read_from_tree(const char *prefix, const char **argv,
-               unsigned char *tree_sha1)
+               unsigned char *tree_sha1, int refresh_flags)
 {
        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
        int index_fd, index_was_discarded = 0;
@@ -152,7 +167,7 @@ static int read_from_tree(const char *prefix, const char **argv,
        if (!index_was_discarded)
                /* The index is still clobbered from do_diff_cache() */
                discard_cache();
-       return update_index_refresh(index_fd, lock);
+       return update_index_refresh(index_fd, lock, refresh_flags);
 }
 
 static void prepend_reflog_action(const char *action, char *buf, size_t size)
@@ -165,9 +180,6 @@ static void prepend_reflog_action(const char *action, char *buf, size_t size)
                warning("Reflog action message too long: %.*s...", 50, buf);
 }
 
-enum reset_type { MIXED, SOFT, HARD, NONE };
-static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };
-
 int cmd_reset(int argc, const char **argv, const char *prefix)
 {
        int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
@@ -182,6 +194,8 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
                OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
                OPT_SET_INT(0, "hard", &reset_type,
                                "reset HEAD, index and working tree", HARD),
+               OPT_SET_INT(0, "merge", &reset_type,
+                               "reset HEAD, index and working tree", MERGE),
                OPT_BOOLEAN('q', NULL, &quiet,
                                "disable showing new HEAD in hard reset and progress message"),
                OPT_END()
@@ -214,7 +228,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
                }
                /*
                 * Otherwise, argv[i] could be either <rev> or <paths> and
-                * has to be unambigous.
+                * has to be unambiguous.
                 */
                else if (!get_sha1(argv[i], sha1)) {
                        /*
@@ -246,7 +260,8 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
                else if (reset_type != NONE)
                        die("Cannot do %s reset with paths.",
                                        reset_type_names[reset_type]);
-               return read_from_tree(prefix, argv + i, sha1);
+               return read_from_tree(prefix, argv + i, sha1,
+                               quiet ? REFRESH_QUIET : REFRESH_SAY_CHANGED);
        }
        if (reset_type == NONE)
                reset_type = MIXED; /* by default */
@@ -261,7 +276,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
                if (is_merge() || read_cache() < 0 || unmerged_cache())
                        die("Cannot do a soft reset in the middle of a merge.");
        }
-       else if (reset_index_file(sha1, (reset_type == HARD), quiet))
+       else if (reset_index_file(sha1, reset_type, quiet))
                die("Could not reset index file to revision '%s'.", rev);
 
        /* Any resets update HEAD to the head being switched to,
@@ -274,7 +289,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
                update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
        }
        else if (old_orig)
-               delete_ref("ORIG_HEAD", old_orig);
+               delete_ref("ORIG_HEAD", old_orig, 0);
        prepend_reflog_action("updating HEAD", msg, sizeof(msg));
        update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 
@@ -286,7 +301,8 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
        case SOFT: /* Nothing else to do. */
                break;
        case MIXED: /* Report what has not been updated. */
-               update_index_refresh(0, NULL);
+               update_index_refresh(0, NULL,
+                               quiet ? REFRESH_QUIET : REFRESH_SAY_CHANGED);
                break;
        }