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authorJunio C Hamano <gitster@pobox.com>2012-07-22 12:55:07 -0700
committerJunio C Hamano <gitster@pobox.com>2012-07-22 12:55:07 -0700
commit0958a24d7360759902f802744c0839c8029659d7 (patch)
treef22a0b0f2cb4dc8e7c4e0b5a053d0bac01c445bf
parent9a0231b395cb9720365b7066312eeaa86e37ed31 (diff)
parent31ffd0c0c1255cb7e9ba76192a70ae294faf95bf (diff)
downloadgit-0958a24d7360759902f802744c0839c8029659d7.tar.gz
Merge branch 'jc/sha1-name-more'
Teaches the object name parser things like a "git describe" output is always a commit object, "A" in "git log A" must be a committish, and "A" and "B" in "git log A...B" both must be committish, etc., to prolong the lifetime of abbreviated object names. * jc/sha1-name-more: (27 commits) t1512: match the "other" object names t1512: ignore whitespaces in wc -l output rev-parse --disambiguate=<prefix> rev-parse: A and B in "rev-parse A..B" refer to committish reset: the command takes committish commit-tree: the command wants a tree and commits apply: --build-fake-ancestor expects blobs sha1_name.c: add support for disambiguating other types revision.c: the "log" family, except for "show", takes committish revision.c: allow handle_revision_arg() to take other flags sha1_name.c: introduce get_sha1_committish() sha1_name.c: teach lookup context to get_sha1_with_context() sha1_name.c: many short names can only be committish sha1_name.c: get_sha1_1() takes lookup flags sha1_name.c: get_describe_name() by definition groks only commits sha1_name.c: teach get_short_sha1() a commit-only option sha1_name.c: allow get_short_sha1() to take other flags get_sha1(): fix error status regression sha1_name.c: restructure disambiguation of short names sha1_name.c: correct misnamed "canonical" and "res" ...
-rw-r--r--Documentation/git-rev-parse.txt6
-rw-r--r--builtin/apply.c2
-rw-r--r--builtin/cat-file.c2
-rw-r--r--builtin/commit-tree.c8
-rw-r--r--builtin/log.c3
-rw-r--r--builtin/pack-objects.c2
-rw-r--r--builtin/reset.c10
-rw-r--r--builtin/rev-parse.c14
-rw-r--r--cache.h28
-rw-r--r--commit.c2
-rw-r--r--revision.c38
-rw-r--r--revision.h5
-rw-r--r--setup.c8
-rw-r--r--sha1_name.c494
-rwxr-xr-xt/t1512-rev-parse-disambiguation.sh264
15 files changed, 714 insertions, 172 deletions
diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index 4cc3e9586f..3c63561f02 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -101,6 +101,12 @@ OPTIONS
The option core.warnAmbiguousRefs is used to select the strict
abbreviation mode.
+--disambiguate=<prefix>::
+ Show every object whose name begins with the given prefix.
+ The <prefix> must be at least 4 hexadecimal digits long to
+ avoid listing each and every object in the repository by
+ mistake.
+
--all::
Show all refs found in `refs/`.
diff --git a/builtin/apply.c b/builtin/apply.c
index ace04c453b..069cf341b6 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -3589,7 +3589,7 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
name = patch->old_name ? patch->old_name : patch->new_name;
if (0 < patch->is_new)
continue;
- else if (get_sha1(patch->old_sha1_prefix, sha1))
+ else if (get_sha1_blob(patch->old_sha1_prefix, sha1))
/* git diff has no index line for mode/type changes */
if (!patch->lines_added && !patch->lines_deleted) {
if (get_current_sha1(patch->old_name, sha1))
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 36a9104433..af74e775a1 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -91,7 +91,7 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
unsigned long size;
struct object_context obj_context;
- if (get_sha1_with_context(obj_name, sha1, &obj_context))
+ if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
die("Not a valid object name %s", obj_name);
buf = NULL;
diff --git a/builtin/commit-tree.c b/builtin/commit-tree.c
index 164b655df9..cb982c5503 100644
--- a/builtin/commit-tree.c
+++ b/builtin/commit-tree.c
@@ -48,8 +48,8 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
if (argc < 2 || !strcmp(argv[1], "-h"))
usage(commit_tree_usage);
- if (get_sha1(argv[1], tree_sha1))
- die("Not a valid object name %s", argv[1]);
+ if (get_sha1_tree(argv[1], tree_sha1))
+ die("Not a valid tree object name %s", argv[1]);
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
@@ -57,7 +57,7 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
unsigned char sha1[20];
if (argc <= ++i)
usage(commit_tree_usage);
- if (get_sha1(argv[i], sha1))
+ if (get_sha1_commit(argv[i], sha1))
die("Not a valid object name %s", argv[i]);
assert_sha1_type(sha1, OBJ_COMMIT);
new_parent(lookup_commit(sha1), &parents);
@@ -104,7 +104,7 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
continue;
}
- if (get_sha1(arg, tree_sha1))
+ if (get_sha1_tree(arg, tree_sha1))
die("Not a valid object name %s", arg);
if (got_tree)
die("Cannot give more than one trees");
diff --git a/builtin/log.c b/builtin/log.c
index adcbcf1f24..ecc2793690 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -367,6 +367,7 @@ int cmd_whatchanged(int argc, const char **argv, const char *prefix)
rev.simplify_history = 0;
memset(&opt, 0, sizeof(opt));
opt.def = "HEAD";
+ opt.revarg_opt = REVARG_COMMITTISH;
cmd_log_init(argc, argv, prefix, &rev, &opt);
if (!rev.diffopt.output_format)
rev.diffopt.output_format = DIFF_FORMAT_RAW;
@@ -557,6 +558,7 @@ int cmd_log(int argc, const char **argv, const char *prefix)
rev.always_show_header = 1;
memset(&opt, 0, sizeof(opt));
opt.def = "HEAD";
+ opt.revarg_opt = REVARG_COMMITTISH;
cmd_log_init(argc, argv, prefix, &rev, &opt);
return cmd_log_walk(&rev);
}
@@ -1132,6 +1134,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
rev.subject_prefix = fmt_patch_subject_prefix;
memset(&s_r_opt, 0, sizeof(s_r_opt));
s_r_opt.def = "HEAD";
+ s_r_opt.revarg_opt = REVARG_COMMITTISH;
if (default_attach) {
rev.mime_boundary = default_attach;
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index f3348208d8..782e7d0c38 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -2373,7 +2373,7 @@ static void get_object_list(int ac, const char **av)
}
die("not a rev '%s'", line);
}
- if (handle_revision_arg(line, &revs, flags, 1))
+ if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
die("bad revision '%s'", line);
}
diff --git a/builtin/reset.c b/builtin/reset.c
index 4cc34c9084..74442bd766 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -276,7 +276,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
* Otherwise, argv[i] could be either <rev> or <paths> and
* has to be unambiguous.
*/
- else if (!get_sha1(argv[i], sha1)) {
+ else if (!get_sha1_committish(argv[i], sha1)) {
/*
* Ok, argv[i] looks like a rev; it should not
* be a filename.
@@ -289,9 +289,15 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
}
}
- if (get_sha1(rev, sha1))
+ if (get_sha1_committish(rev, sha1))
die(_("Failed to resolve '%s' as a valid ref."), rev);
+ /*
+ * NOTE: As "git reset $treeish -- $path" should be usable on
+ * any tree-ish, this is not strictly correct. We are not
+ * moving the HEAD to any commit; we are merely resetting the
+ * entries in the index to that of a treeish.
+ */
commit = lookup_commit_reference(sha1);
if (!commit)
die(_("Could not parse object '%s'."), rev);
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 13495b88f5..32788a9f86 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -195,6 +195,12 @@ static int anti_reference(const char *refname, const unsigned char *sha1, int fl
return 0;
}
+static int show_abbrev(const unsigned char *sha1, void *cb_data)
+{
+ show_rev(NORMAL, sha1, NULL);
+ return 0;
+}
+
static void show_datestring(const char *flag, const char *datestr)
{
static char buffer[100];
@@ -238,7 +244,7 @@ static int try_difference(const char *arg)
next = "HEAD";
if (dotdot == arg)
this = "HEAD";
- if (!get_sha1(this, sha1) && !get_sha1(next, end)) {
+ if (!get_sha1_committish(this, sha1) && !get_sha1_committish(next, end)) {
show_rev(NORMAL, end, next);
show_rev(symmetric ? NORMAL : REVERSED, sha1, this);
if (symmetric) {
@@ -278,7 +284,7 @@ static int try_parent_shorthands(const char *arg)
return 0;
*dotdot = 0;
- if (get_sha1(arg, sha1))
+ if (get_sha1_committish(arg, sha1))
return 0;
if (!parents_only)
@@ -589,6 +595,10 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
for_each_ref(show_reference, NULL);
continue;
}
+ if (!prefixcmp(arg, "--disambiguate=")) {
+ for_each_abbrev(arg + 15, show_abbrev, NULL);
+ continue;
+ }
if (!strcmp(arg, "--bisect")) {
for_each_ref_in("refs/bisect/bad", show_reference, NULL);
for_each_ref_in("refs/bisect/good", anti_reference, NULL);
diff --git a/cache.h b/cache.h
index 6a1aff5e2a..2997b918e8 100644
--- a/cache.h
+++ b/cache.h
@@ -790,17 +790,25 @@ struct object_context {
unsigned mode;
};
+#define GET_SHA1_QUIETLY 01
+#define GET_SHA1_COMMIT 02
+#define GET_SHA1_COMMITTISH 04
+#define GET_SHA1_TREE 010
+#define GET_SHA1_TREEISH 020
+#define GET_SHA1_BLOB 040
+#define GET_SHA1_ONLY_TO_DIE 04000
+
extern int get_sha1(const char *str, unsigned char *sha1);
-extern int get_sha1_with_mode_1(const char *str, unsigned char *sha1, unsigned *mode, int only_to_die, const char *prefix);
-static inline int get_sha1_with_mode(const char *str, unsigned char *sha1, unsigned *mode)
-{
- return get_sha1_with_mode_1(str, sha1, mode, 0, NULL);
-}
-extern int get_sha1_with_context_1(const char *name, unsigned char *sha1, struct object_context *orc, int only_to_die, const char *prefix);
-static inline int get_sha1_with_context(const char *str, unsigned char *sha1, struct object_context *orc)
-{
- return get_sha1_with_context_1(str, sha1, orc, 0, NULL);
-}
+extern int get_sha1_commit(const char *str, unsigned char *sha1);
+extern int get_sha1_committish(const char *str, unsigned char *sha1);
+extern int get_sha1_tree(const char *str, unsigned char *sha1);
+extern int get_sha1_treeish(const char *str, unsigned char *sha1);
+extern int get_sha1_blob(const char *str, unsigned char *sha1);
+extern void maybe_die_on_misspelt_object_name(const char *name, const char *prefix);
+extern int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc);
+
+typedef int each_abbrev_fn(const unsigned char *sha1, void *);
+extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);
/*
* Try to read a SHA1 in hexadecimal format from the 40 characters
diff --git a/commit.c b/commit.c
index 8248a994a5..42af4c1f23 100644
--- a/commit.c
+++ b/commit.c
@@ -68,7 +68,7 @@ struct commit *lookup_commit_reference_by_name(const char *name)
unsigned char sha1[20];
struct commit *commit;
- if (get_sha1(name, sha1))
+ if (get_sha1_committish(name, sha1))
return NULL;
commit = lookup_commit_reference(sha1);
if (!commit || parse_commit(commit))
diff --git a/revision.c b/revision.c
index 5b81a92e3a..c64bf68fa1 100644
--- a/revision.c
+++ b/revision.c
@@ -1000,7 +1000,7 @@ static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
flags ^= UNINTERESTING;
arg++;
}
- if (get_sha1(arg, sha1))
+ if (get_sha1_committish(arg, sha1))
return 0;
while (1) {
it = get_reference(revs, arg, sha1, 0);
@@ -1114,16 +1114,16 @@ static void prepare_show_merge(struct rev_info *revs)
revs->limited = 1;
}
-int handle_revision_arg(const char *arg_, struct rev_info *revs,
- int flags,
- int cant_be_filename)
+int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
{
- unsigned mode;
+ struct object_context oc;
char *dotdot;
struct object *object;
unsigned char sha1[20];
int local_flags;
const char *arg = arg_;
+ int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
+ unsigned get_sha1_flags = 0;
dotdot = strstr(arg, "..");
if (dotdot) {
@@ -1141,8 +1141,8 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs,
next = "HEAD";
if (dotdot == arg)
this = "HEAD";
- if (!get_sha1(this, from_sha1) &&
- !get_sha1(next, sha1)) {
+ if (!get_sha1_committish(this, from_sha1) &&
+ !get_sha1_committish(next, sha1)) {
struct commit *a, *b;
struct commit_list *exclude;
@@ -1201,13 +1201,17 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs,
local_flags = UNINTERESTING;
arg++;
}
- if (get_sha1_with_mode(arg, sha1, &mode))
+
+ if (revarg_opt & REVARG_COMMITTISH)
+ get_sha1_flags = GET_SHA1_COMMITTISH;
+
+ if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
return revs->ignore_missing ? 0 : -1;
if (!cant_be_filename)
verify_non_filename(revs->prefix, arg);
object = get_reference(revs, arg, sha1, flags ^ local_flags);
add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
- add_pending_object_with_mode(revs, object, arg, mode);
+ add_pending_object_with_mode(revs, object, arg, oc.mode);
return 0;
}
@@ -1257,7 +1261,7 @@ static void read_revisions_from_stdin(struct rev_info *revs,
}
die("options not supported in --stdin mode");
}
- if (handle_revision_arg(sb.buf, revs, 0, 1))
+ if (handle_revision_arg(sb.buf, revs, 0, REVARG_CANNOT_BE_FILENAME))
die("bad revision '%s'", sb.buf);
}
if (seen_dashdash)
@@ -1708,7 +1712,7 @@ static int handle_revision_pseudo_opt(const char *submodule,
*/
int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
{
- int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0;
+ int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
struct cmdline_pathspec prune_data;
const char *submodule = NULL;
@@ -1736,6 +1740,9 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
/* Second, deal with arguments and options */
flags = 0;
+ revarg_opt = opt ? opt->revarg_opt : 0;
+ if (seen_dashdash)
+ revarg_opt |= REVARG_CANNOT_BE_FILENAME;
read_from_stdin = 0;
for (left = i = 1; i < argc; i++) {
const char *arg = argv[i];
@@ -1771,7 +1778,8 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
continue;
}
- if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
+
+ if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
int j;
if (seen_dashdash || *arg == '^')
die("bad revision '%s'", arg);
@@ -1822,11 +1830,11 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
if (revs->def && !revs->pending.nr && !got_rev_arg) {
unsigned char sha1[20];
struct object *object;
- unsigned mode;
- if (get_sha1_with_mode(revs->def, sha1, &mode))
+ struct object_context oc;
+ if (get_sha1_with_context(revs->def, 0, sha1, &oc))
die("bad default revision '%s'", revs->def);
object = get_reference(revs, revs->def, sha1, 0);
- add_pending_object_with_mode(revs, object, revs->def, mode);
+ add_pending_object_with_mode(revs, object, revs->def, oc.mode);
}
/* Did the user ask for any diff output? Run the diff! */
diff --git a/revision.h b/revision.h
index 863f4f6454..cb5ab3513b 100644
--- a/revision.h
+++ b/revision.h
@@ -184,6 +184,7 @@ struct setup_revision_opt {
void (*tweak)(struct rev_info *, struct setup_revision_opt *);
const char *submodule;
int assume_dashdash;
+ unsigned revarg_opt;
};
extern void init_revisions(struct rev_info *revs, const char *prefix);
@@ -191,7 +192,9 @@ extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, s
extern void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
const struct option *options,
const char * const usagestr[]);
-extern int handle_revision_arg(const char *arg, struct rev_info *revs,int flags,int cant_be_filename);
+#define REVARG_CANNOT_BE_FILENAME 01
+#define REVARG_COMMITTISH 02
+extern int handle_revision_arg(const char *arg, struct rev_info *revs, int flags, unsigned revarg_opt);
extern void reset_revision_walk(void);
extern int prepare_revision_walk(struct rev_info *revs);
diff --git a/setup.c b/setup.c
index e11497720e..9139beefc7 100644
--- a/setup.c
+++ b/setup.c
@@ -77,9 +77,6 @@ static void NORETURN die_verify_filename(const char *prefix,
const char *arg,
int diagnose_misspelt_rev)
{
- unsigned char sha1[20];
- unsigned mode;
-
if (!diagnose_misspelt_rev)
die("%s: no such path in the working tree.\n"
"Use '-- <path>...' to specify paths that do not exist locally.",
@@ -88,11 +85,10 @@ static void NORETURN die_verify_filename(const char *prefix,
* Saying "'(icase)foo' does not exist in the index" when the
* user gave us ":(icase)foo" is just stupid. A magic pathspec
* begins with a colon and is followed by a non-alnum; do not
- * let get_sha1_with_mode_1(only_to_die=1) to even trigger.
+ * let maybe_die_on_misspelt_object_name() even trigger.
*/
if (!(arg[0] == ':' && !isalnum(arg[1])))
- /* try a detailed diagnostic ... */
- get_sha1_with_mode_1(arg, sha1, &mode, 1, prefix);
+ maybe_die_on_misspelt_object_name(arg, prefix);
/* ... or fall back the most general message. */
die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
diff --git a/sha1_name.c b/sha1_name.c
index 5d81ea0564..95003c77ea 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -9,14 +9,82 @@
static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
-static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
+typedef int (*disambiguate_hint_fn)(const unsigned char *, void *);
+
+struct disambiguate_state {
+ disambiguate_hint_fn fn;
+ void *cb_data;
+ unsigned char candidate[20];
+ unsigned candidate_exists:1;
+ unsigned candidate_checked:1;
+ unsigned candidate_ok:1;
+ unsigned disambiguate_fn_used:1;
+ unsigned ambiguous:1;
+ unsigned always_call_fn:1;
+};
+
+static void update_candidates(struct disambiguate_state *ds, const unsigned char *current)
+{
+ if (ds->always_call_fn) {
+ ds->ambiguous = ds->fn(current, ds->cb_data) ? 1 : 0;
+ return;
+ }
+ if (!ds->candidate_exists) {
+ /* this is the first candidate */
+ hashcpy(ds->candidate, current);
+ ds->candidate_exists = 1;
+ return;
+ } else if (!hashcmp(ds->candidate, current)) {
+ /* the same as what we already have seen */
+ return;
+ }
+
+ if (!ds->fn) {
+ /* cannot disambiguate between ds->candidate and current */
+ ds->ambiguous = 1;
+ return;
+ }
+
+ if (!ds->candidate_checked) {
+ ds->candidate_ok = ds->fn(ds->candidate, ds->cb_data);
+ ds->disambiguate_fn_used = 1;
+ ds->candidate_checked = 1;
+ }
+
+ if (!ds->candidate_ok) {
+ /* discard the candidate; we know it does not satisify fn */
+ hashcpy(ds->candidate, current);
+ ds->candidate_checked = 0;
+ return;
+ }
+
+ /* if we reach this point, we know ds->candidate satisfies fn */
+ if (ds->fn(current, ds->cb_data)) {
+ /*
+ * if both current and candidate satisfy fn, we cannot
+ * disambiguate.
+ */
+ ds->candidate_ok = 0;
+ ds->ambiguous = 1;
+ }
+
+ /* otherwise, current can be discarded and candidate is still good */
+}
+
+static void find_short_object_filename(int len, const char *hex_pfx, struct disambiguate_state *ds)
{
struct alternate_object_database *alt;
char hex[40];
- int found = 0;
static struct alternate_object_database *fakeent;
if (!fakeent) {
+ /*
+ * Create a "fake" alternate object database that
+ * points to our own object database, to make it
+ * easier to get a temporary working space in
+ * alt->name/alt->base while iterating over the
+ * object databases including our own.
+ */
const char *objdir = get_object_directory();
int objdir_len = strlen(objdir);
int entlen = objdir_len + 43;
@@ -27,33 +95,28 @@ static int find_short_object_filename(int len, const char *name, unsigned char *
}
fakeent->next = alt_odb_list;
- sprintf(hex, "%.2s", name);
- for (alt = fakeent; alt && found < 2; alt = alt->next) {
+ sprintf(hex, "%.2s", hex_pfx);
+ for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
struct dirent *de;
DIR *dir;
- sprintf(alt->name, "%.2s/", name);
+ sprintf(alt->name, "%.2s/", hex_pfx);
dir = opendir(alt->base);
if (!dir)
continue;
- while ((de = readdir(dir)) != NULL) {
+
+ while (!ds->ambiguous && (de = readdir(dir)) != NULL) {
+ unsigned char sha1[20];
+
if (strlen(de->d_name) != 38)
continue;
- if (memcmp(de->d_name, name + 2, len - 2))
+ if (memcmp(de->d_name, hex_pfx + 2, len - 2))
continue;
- if (!found) {
- memcpy(hex + 2, de->d_name, 38);
- found++;
- }
- else if (memcmp(hex + 2, de->d_name, 38)) {
- found = 2;
- break;
- }
+ memcpy(hex + 2, de->d_name, 38);
+ if (!get_sha1_hex(hex, sha1))
+ update_candidates(ds, sha1);
}
closedir(dir);
}
- if (found == 1)
- return get_sha1_hex(hex, sha1) == 0;
- return found;
}
static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
@@ -71,103 +134,157 @@ static int match_sha(unsigned len, const unsigned char *a, const unsigned char *
return 1;
}
-static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
+static void unique_in_pack(int len,
+ const unsigned char *bin_pfx,
+ struct packed_git *p,
+ struct disambiguate_state *ds)
{
- struct packed_git *p;
- const unsigned char *found_sha1 = NULL;
- int found = 0;
-
- prepare_packed_git();
- for (p = packed_git; p && found < 2; p = p->next) {
- uint32_t num, last;
- uint32_t first = 0;
- open_pack_index(p);
- num = p->num_objects;
- last = num;
- while (first < last) {
- uint32_t mid = (first + last) / 2;
- const unsigned char *now;
- int cmp;
-
- now = nth_packed_object_sha1(p, mid);
- cmp = hashcmp(match, now);
- if (!cmp) {
- first = mid;
- break;
- }
- if (cmp > 0) {
- first = mid+1;
- continue;
- }
- last = mid;
+ uint32_t num, last, i, first = 0;
+ const unsigned char *current = NULL;
+
+ open_pack_index(p);
+ num = p->num_objects;
+ last = num;
+ while (first < last) {
+ uint32_t mid = (first + last) / 2;
+ const unsigned char *current;
+ int cmp;
+
+ current = nth_packed_object_sha1(p, mid);
+ cmp = hashcmp(bin_pfx, current);
+ if (!cmp) {
+ first = mid;
+ break;
}
- if (first < num) {
- const unsigned char *now, *next;
- now = nth_packed_object_sha1(p, first);
- if (match_sha(len, match, now)) {
- next = nth_packed_object_sha1(p, first+1);
- if (!next|| !match_sha(len, match, next)) {
- /* unique within this pack */
- if (!found) {
- found_sha1 = now;
- found++;
- }
- else if (hashcmp(found_sha1, now)) {
- found = 2;
- break;
- }
- }
- else {
- /* not even unique within this pack */
- found = 2;
- break;
- }
- }
+ if (cmp > 0) {
+ first = mid+1;
+ continue;
}
+ last = mid;
+ }
+
+ /*
+ * At this point, "first" is the location of the lowest object
+ * with an object name that could match "bin_pfx". See if we have
+ * 0, 1 or more objects that actually match(es).
+ */
+ for (i = first; i < num && !ds->ambiguous; i++) {
+ current = nth_packed_object_sha1(p, i);
+ if (!match_sha(len, bin_pfx, current))
+ break;
+ update_candidates(ds, current);
}
- if (found == 1)
- hashcpy(sha1, found_sha1);
- return found;
+}
+
+static void find_short_packed_object(int len, const unsigned char *bin_pfx,
+ struct disambiguate_state *ds)
+{
+ struct packed_git *p;
+
+ prepare_packed_git();
+ for (p = packed_git; p && !ds->ambiguous; p = p->next)
+ unique_in_pack(len, bin_pfx, p, ds);
}
#define SHORT_NAME_NOT_FOUND (-1)
#define SHORT_NAME_AMBIGUOUS (-2)
-static int find_unique_short_object(int len, char *canonical,
- unsigned char *res, unsigned char *sha1)
+static int finish_object_disambiguation(struct disambiguate_state *ds,
+ unsigned char *sha1)
{
- int has_unpacked, has_packed;
- unsigned char unpacked_sha1[20], packed_sha1[20];
+ if (ds->ambiguous)
+ return SHORT_NAME_AMBIGUOUS;
- prepare_alt_odb();
- has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
- has_packed = find_short_packed_object(len, res, packed_sha1);
- if (!has_unpacked && !has_packed)
+ if (!ds->candidate_exists)
return SHORT_NAME_NOT_FOUND;
- if (1 < has_unpacked || 1 < has_packed)
+
+ if (!ds->candidate_checked)
+ /*
+ * If this is the only candidate, there is no point
+ * calling the disambiguation hint callback.
+ *
+ * On the other hand, if the current candidate
+ * replaced an earlier candidate that did _not_ pass
+ * the disambiguation hint callback, then we do have
+ * more than one objects that match the short name
+ * given, so we should make sure this one matches;
+ * otherwise, if we discovered this one and the one
+ * that we previously discarded in the reverse order,
+ * we would end up showing different results in the
+ * same repository!
+ */
+ ds->candidate_ok = (!ds->disambiguate_fn_used ||
+ ds->fn(ds->candidate, ds->cb_data));
+
+ if (!ds->candidate_ok)
return SHORT_NAME_AMBIGUOUS;
- if (has_unpacked != has_packed) {
- hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
+
+ hashcpy(sha1, ds->candidate);
+ return 0;
+}
+
+static int disambiguate_commit_only(const unsigned char *sha1, void *cb_data_unused)
+{
+ int kind = sha1_object_info(sha1, NULL);
+ return kind == OBJ_COMMIT;
+}
+
+static int disambiguate_committish_only(const unsigned char *sha1, void *cb_data_unused)
+{
+ struct object *obj;
+ int kind;
+
+ kind = sha1_object_info(sha1, NULL);
+ if (kind == OBJ_COMMIT)
+ return 1;
+ if (kind != OBJ_TAG)
return 0;
- }
- /* Both have unique ones -- do they match? */
- if (hashcmp(packed_sha1, unpacked_sha1))
- return SHORT_NAME_AMBIGUOUS;
- hashcpy(sha1, packed_sha1);
+
+ /* We need to do this the hard way... */
+ obj = deref_tag(lookup_object(sha1), NULL, 0);
+ if (obj && obj->type == OBJ_COMMIT)
+ return 1;
return 0;
}
-static int get_short_sha1(const char *name, int len, unsigned char *sha1,
- int quietly)
+static int disambiguate_tree_only(const unsigned char *sha1, void *cb_data_unused)
{
- int i, status;
- char canonical[40];
- unsigned char res[20];
+ int kind = sha1_object_info(sha1, NULL);
+ return kind == OBJ_TREE;
+}
- if (len < MINIMUM_ABBREV || len > 40)
- return -1;
- hashclr(res);
- memset(canonical, 'x', 40);
+static int disambiguate_treeish_only(const unsigned char *sha1, void *cb_data_unused)
+{
+ struct object *obj;
+ int kind;
+
+ kind = sha1_object_info(sha1, NULL);
+ if (kind == OBJ_TREE || kind == OBJ_COMMIT)
+ return 1;
+ if (kind != OBJ_TAG)
+ return 0;
+
+ /* We need to do this the hard way... */
+ obj = deref_tag(lookup_object(sha1), NULL, 0);
+ if (obj && (obj->type == OBJ_TREE || obj->type == OBJ_COMMIT))
+ return 1;
+ return 0;
+}
+
+static int disambiguate_blob_only(const unsigned char *sha1, void *cb_data_unused)
+{
+ int kind = sha1_object_info(sha1, NULL);
+ return kind == OBJ_BLOB;
+}
+
+static int prepare_prefixes(const char *name, int len,
+ unsigned char *bin_pfx,
+ char *hex_pfx)
+{
+ int i;
+
+ hashclr(bin_pfx);
+ memset(hex_pfx, 'x', 40);
for (i = 0; i < len ;i++) {
unsigned char c = name[i];
unsigned char val;
@@ -181,18 +298,76 @@ static int get_short_sha1(const char *name, int len, unsigned char *sha1,
}
else
return -1;
- canonical[i] = c;
+ hex_pfx[i] = c;
if (!(i & 1))
val <<= 4;
- res[i >> 1] |= val;
+ bin_pfx[i >> 1] |= val;
}
+ return 0;
+}
+
+static int get_short_sha1(const char *name, int len, unsigned char *sha1,
+ unsigned flags)
+{
+ int status;
+ char hex_pfx[40];
+ unsigned char bin_pfx[20];
+ struct disambiguate_state ds;
+ int quietly = !!(flags & GET_SHA1_QUIETLY);
+
+ if (len < MINIMUM_ABBREV || len > 40)
+ return -1;
+ if (prepare_prefixes(name, len, bin_pfx, hex_pfx) < 0)
+ return -1;
+
+ prepare_alt_odb();
+
+ memset(&ds, 0, sizeof(ds));
+ if (flags & GET_SHA1_COMMIT)
+ ds.fn = disambiguate_commit_only;
+ else if (flags & GET_SHA1_COMMITTISH)
+ ds.fn = disambiguate_committish_only;
+ else if (flags & GET_SHA1_TREE)
+ ds.fn = disambiguate_tree_only;
+ else if (flags & GET_SHA1_TREEISH)
+ ds.fn = disambiguate_treeish_only;
+ else if (flags & GET_SHA1_BLOB)
+ ds.fn = disambiguate_blob_only;
+
+ find_short_object_filename(len, hex_pfx, &ds);
+ find_short_packed_object(len, bin_pfx, &ds);
+ status = finish_object_disambiguation(&ds, sha1);
- status = find_unique_short_object(i, canonical, res, sha1);
if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
- return error("short SHA1 %.*s is ambiguous.", len, canonical);
+ return error("short SHA1 %.*s is ambiguous.", len, hex_pfx);
return status;
}
+
+int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
+{
+ char hex_pfx[40];
+ unsigned char bin_pfx[20];
+ struct disambiguate_state ds;
+ int len = strlen(prefix);
+
+ if (len < MINIMUM_ABBREV || len > 40)
+ return -1;
+ if (prepare_prefixes(prefix, len, bin_pfx, hex_pfx) < 0)
+ return -1;
+
+ prepare_alt_odb();
+
+ memset(&ds, 0, sizeof(ds));
+ ds.always_call_fn = 1;
+ ds.cb_data = cb_data;
+ ds.fn = fn;
+
+ find_short_object_filename(len, hex_pfx, &ds);
+ find_short_packed_object(len, bin_pfx, &ds);
+ return ds.ambiguous;
+}
+
const char *find_unique_abbrev(const unsigned char *sha1, int len)
{
int status, exists;
@@ -204,7 +379,7 @@ const char *find_unique_abbrev(const unsigned char *sha1, int len)
return hex;
while (len < 40) {
unsigned char sha1_ret[20];
- status = get_short_sha1(hex, len, sha1_ret, 1);
+ status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
if (exists
? !status
: status == SHORT_NAME_NOT_FOUND) {
@@ -255,7 +430,7 @@ static inline int upstream_mark(const char *string, int len)
return 0;
}
-static int get_sha1_1(const char *name, int len, unsigned char *sha1);
+static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
{
@@ -292,7 +467,7 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
ret = interpret_branch_name(str+at, &buf);
if (ret > 0) {
/* substitute this branch name and restart */
- return get_sha1_1(buf.buf, buf.len, sha1);
+ return get_sha1_1(buf.buf, buf.len, sha1, 0);
} else if (ret == 0) {
return -1;
}
@@ -362,7 +537,7 @@ static int get_parent(const char *name, int len,
unsigned char *result, int idx)
{
unsigned char sha1[20];
- int ret = get_sha1_1(name, len, sha1);
+ int ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
struct commit *commit;
struct commit_list *p;
@@ -395,7 +570,7 @@ static int get_nth_ancestor(const char *name, int len,
struct commit *commit;
int ret;
- ret = get_sha1_1(name, len, sha1);
+ ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
if (ret)
return ret;
commit = lookup_commit_reference(sha1);
@@ -441,6 +616,7 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
unsigned char outer[20];
const char *sp;
unsigned int expected_type = 0;
+ unsigned lookup_flags = 0;
struct object *o;
/*
@@ -476,7 +652,10 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
else
return -1;
- if (get_sha1_1(name, sp - name - 2, outer))
+ if (expected_type == OBJ_COMMIT)
+ lookup_flags = GET_SHA1_COMMITTISH;
+
+ if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
return -1;
o = parse_object(outer);
@@ -525,6 +704,7 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
static int get_describe_name(const char *name, int len, unsigned char *sha1)
{
const char *cp;
+ unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
for (cp = name + len - 1; name + 2 <= cp; cp--) {
char ch = *cp;
@@ -535,14 +715,14 @@ static int get_describe_name(const char *name, int len, unsigned char *sha1)
if (ch == 'g' && cp[-1] == '-') {
cp++;
len -= cp - name;
- return get_short_sha1(cp, len, sha1, 1);
+ return get_short_sha1(cp, len, sha1, flags);
}
}
}
return -1;
}
-static int get_sha1_1(const char *name, int len, unsigned char *sha1)
+static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
{
int ret, has_suffix;
const char *cp;
@@ -587,7 +767,7 @@ static int get_sha1_1(const char *name, int len, unsigned char *sha1)
if (!ret)
return 0;
- return get_short_sha1(name, len, sha1, 0);
+ return get_short_sha1(name, len, sha1, lookup_flags);
}
/*
@@ -769,7 +949,7 @@ int get_sha1_mb(const char *name, unsigned char *sha1)
struct strbuf sb;
strbuf_init(&sb, dots - name);
strbuf_add(&sb, name, dots - name);
- st = get_sha1(sb.buf, sha1_tmp);
+ st = get_sha1_committish(sb.buf, sha1_tmp);
strbuf_release(&sb);
}
if (st)
@@ -778,7 +958,7 @@ int get_sha1_mb(const char *name, unsigned char *sha1)
if (!one)
return -1;
- if (get_sha1(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
+ if (get_sha1_committish(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
return -1;
two = lookup_commit_reference_gently(sha1_tmp, 0);
if (!two)
@@ -905,7 +1085,52 @@ int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
int get_sha1(const char *name, unsigned char *sha1)
{
struct object_context unused;
- return get_sha1_with_context(name, sha1, &unused);
+ return get_sha1_with_context(name, 0, sha1, &unused);
+}
+
+/*
+ * Many callers know that the user meant to name a committish by
+ * syntactical positions where the object name appears. Calling this
+ * function allows the machinery to disambiguate shorter-than-unique
+ * abbreviated object names between committish and others.
+ *
+ * Note that this does NOT error out when the named object is not a
+ * committish. It is merely to give a hint to the disambiguation
+ * machinery.
+ */
+int get_sha1_committish(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_COMMITTISH,
+ sha1, &unused);
+}
+
+int get_sha1_treeish(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_TREEISH,
+ sha1, &unused);
+}
+
+int get_sha1_commit(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_COMMIT,
+ sha1, &unused);
+}
+
+int get_sha1_tree(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_TREE,
+ sha1, &unused);
+}
+
+int get_sha1_blob(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_BLOB,
+ sha1, &unused);
}
/* Must be called only when object_name:filename doesn't exist. */
@@ -1004,16 +1229,6 @@ static void diagnose_invalid_index_path(int stage,
}
-int get_sha1_with_mode_1(const char *name, unsigned char *sha1, unsigned *mode,
- int only_to_die, const char *prefix)
-{
- struct object_context oc;
- int ret;
- ret = get_sha1_with_context_1(name, sha1, &oc, only_to_die, prefix);
- *mode = oc.mode;
- return ret;
-}
-
static char *resolve_relative_path(const char *rel)
{
if (prefixcmp(rel, "./") && prefixcmp(rel, "../"))
@@ -1031,20 +1246,24 @@ static char *resolve_relative_path(const char *rel)
rel);
}
-int get_sha1_with_context_1(const char *name, unsigned char *sha1,
- struct object_context *oc,
- int only_to_die, const char *prefix)
+static int get_sha1_with_context_1(const char *name,
+ unsigned flags,
+ const char *prefix,
+ unsigned char *sha1,
+ struct object_context *oc)
{
int ret, bracket_depth;
int namelen = strlen(name);
const char *cp;
+ int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
memset(oc, 0, sizeof(*oc));
oc->mode = S_IFINVALID;
- ret = get_sha1_1(name, namelen, sha1);
+ ret = get_sha1_1(name, namelen, sha1, flags);
if (!ret)
return ret;
- /* sha1:path --> object name of path in ent sha1
+ /*
+ * sha1:path --> object name of path in ent sha1
* :path -> object name of absolute path in index
* :./path -> object name of path relative to cwd in index
* :[0-3]:path -> object name of path in index at stage
@@ -1119,7 +1338,7 @@ int get_sha1_with_context_1(const char *name, unsigned char *sha1,
strncpy(object_name, name, cp-name);
object_name[cp-name] = '\0';
}
- if (!get_sha1_1(name, cp-name, tree_sha1)) {
+ if (!get_sha1_1(name, cp-name, tree_sha1, GET_SHA1_TREEISH)) {
const char *filename = cp+1;
char *new_filename = NULL;
@@ -1146,3 +1365,22 @@ int get_sha1_with_context_1(const char *name, unsigned char *sha1,
}
return ret;
}
+
+/*
+ * Call this function when you know "name" given by the end user must
+ * name an object but it doesn't; the function _may_ die with a better
+ * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
+ * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
+ * you have a chance to diagnose the error further.
+ */
+void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
+{
+ struct object_context oc;
+ unsigned char sha1[20];
+ get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
+}
+
+int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
+{
+ return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
+}
diff --git a/t/t1512-rev-parse-disambiguation.sh b/t/t1512-rev-parse-disambiguation.sh
new file mode 100755
index 0000000000..6b3d797cea
--- /dev/null
+++ b/t/t1512-rev-parse-disambiguation.sh
@@ -0,0 +1,264 @@
+#!/bin/sh
+
+test_description='object name disambiguation
+
+Create blobs, trees, commits and a tag that all share the same
+prefix, and make sure "git rev-parse" can take advantage of
+type information to disambiguate short object names that are
+not necessarily unique.
+
+The final history used in the test has five commits, with the bottom
+one tagged as v1.0.0. They all have one regular file each.
+
+ +-------------------------------------------+
+ | |
+ | .-------b3wettvi---- ad2uee |
+ | / / |
+ | a2onsxbvj---czy8f73t--ioiley5o |
+ | |
+ +-------------------------------------------+
+
+'
+
+. ./test-lib.sh
+
+test_expect_success 'blob and tree' '
+ test_tick &&
+ (
+ for i in 0 1 2 3 4 5 6 7 8 9
+ do
+ echo $i
+ done
+ echo
+ echo b1rwzyc3
+ ) >a0blgqsjc &&
+
+ # create one blob 0000000000b36
+ git add a0blgqsjc &&
+
+ # create one tree 0000000000cdc
+ git write-tree
+'
+
+test_expect_success 'warn ambiguity when no candidate matches type hint' '
+ test_must_fail git rev-parse --verify 000000000^{commit} 2>actual &&
+ grep "short SHA1 000000000 is ambiguous" actual
+'
+
+test_expect_success 'disambiguate tree-ish' '
+ # feed tree-ish in an unambiguous way
+ git rev-parse --verify 0000000000cdc:a0blgqsjc &&
+
+ # ambiguous at the object name level, but there is only one
+ # such tree-ish (the other is a blob)
+ git rev-parse --verify 000000000:a0blgqsjc
+'
+
+test_expect_success 'disambiguate blob' '
+ sed -e "s/|$//" >patch <<-EOF &&
+ diff --git a/frotz b/frotz
+ index 000000000..ffffff 100644
+ --- a/frotz
+ +++ b/frotz
+ @@ -10,3 +10,4 @@
+ 9
+ |
+ b1rwzyc3
+ +irwry
+ EOF
+ (
+ GIT_INDEX_FILE=frotz &&
+ export GIT_INDEX_FILE &&
+ git apply --build-fake-ancestor frotz patch &&
+ git cat-file blob :frotz >actual
+ ) &&
+ test_cmp a0blgqsjc actual
+'
+
+test_expect_success 'disambiguate tree' '
+ commit=$(echo "d7xm" | git commit-tree 000000000) &&
+ test $(git rev-parse $commit^{tree}) = $(git rev-parse 0000000000cdc)
+'
+
+test_expect_success 'first commit' '
+ # create one commit 0000000000e4f
+ git commit -m a2onsxbvj
+'
+
+test_expect_success 'disambiguate commit-ish' '
+ # feed commit-ish in an unambiguous way
+ git rev-parse --verify 0000000000e4f^{commit} &&
+
+ # ambiguous at the object name level, but there is only one
+ # such commit (the others are tree and blob)
+ git rev-parse --verify 000000000^{commit} &&
+
+ # likewise
+ git rev-parse --verify 000000000^0
+'
+
+test_expect_success 'disambiguate commit' '
+ commit=$(echo "hoaxj" | git commit-tree 0000000000cdc -p 000000000) &&
+ test $(git rev-parse $commit^) = $(git rev-parse 0000000000e4f)
+'
+
+test_expect_success 'log name1..name2 takes only commit-ishes on both ends' '
+ git log 000000000..000000000 &&
+ git log ..000000000 &&
+ git log 000000000.. &&
+ git log 000000000...000000000 &&
+ git log ...000000000 &&
+ git log 000000000...
+'
+
+test_expect_success 'rev-parse name1..name2 takes only commit-ishes on both ends' '
+ git rev-parse 000000000..000000000 &&
+ git rev-parse ..000000000 &&
+ git rev-parse 000000000..
+'
+
+test_expect_success 'git log takes only commit-ish' '
+ git log 000000000
+'
+
+test_expect_success 'git reset takes only commit-ish' '
+ git reset 000000000
+'
+
+test_expect_success 'first tag' '
+ # create one tag 0000000000f8f
+ git tag -a -m j7cp83um v1.0.0
+'
+
+test_expect_failure 'two semi-ambiguous commit-ish' '
+ # Once the parser becomes ultra-smart, it could notice that
+ # 110282 before ^{commit} name many different objects, but
+ # that only two (HEAD and v1.0.0 tag) can be peeled to commit,
+ # and that peeling them down to commit yield the same commit
+ # without ambiguity.
+ git rev-parse --verify 110282^{commit} &&
+
+ # likewise
+ git log 000000000..000000000 &&
+ git log ..000000000 &&
+ git log 000000000.. &&
+ git log 000000000...000000000 &&
+ git log ...000000000 &&
+ git log 000000000...
+'
+
+test_expect_failure 'three semi-ambiguous tree-ish' '
+ # Likewise for tree-ish. HEAD, v1.0.0 and HEAD^{tree} share
+ # the prefix but peeling them to tree yields the same thing
+ git rev-parse --verify 000000000^{tree}
+'
+
+test_expect_success 'parse describe name' '
+ # feed an unambiguous describe name
+ git rev-parse --verify v1.0.0-0-g0000000000e4f &&
+
+ # ambiguous at the object name level, but there is only one
+ # such commit (others are blob, tree and tag)
+ git rev-parse --verify v1.0.0-0-g000000000
+'
+
+test_expect_success 'more history' '
+ # commit 0000000000043
+ git mv a0blgqsjc d12cr3h8t &&
+ echo h62xsjeu >>d12cr3h8t &&
+ git add d12cr3h8t &&
+
+ test_tick &&
+ git commit -m czy8f73t &&
+
+ # commit 00000000008ec
+ git mv d12cr3h8t j000jmpzn &&
+ echo j08bekfvt >>j000jmpzn &&
+ git add j000jmpzn &&
+
+ test_tick &&
+ git commit -m ioiley5o &&
+
+ # commit 0000000005b0
+ git checkout v1.0.0^0 &&
+ git mv a0blgqsjc f5518nwu &&
+
+ for i in h62xsjeu j08bekfvt kg7xflhm
+ do
+ echo $i
+ done >>f5518nwu &&
+ git add f5518nwu &&
+
+ test_tick &&
+ git commit -m b3wettvi &&
+ side=$(git rev-parse HEAD) &&
+
+ # commit 000000000066
+ git checkout master &&
+
+ # If you use recursive, merge will fail and you will need to
+ # clean up a0blgqsjc as well. If you use resolve, merge will
+ # succeed.
+ test_might_fail git merge --no-commit -s recursive $side &&
+ git rm -f f5518nwu j000jmpzn &&
+
+ test_might_fail git rm -f a0blgqsjc &&
+ (
+ git cat-file blob $side:f5518nwu
+ echo j3l0i9s6
+ ) >ab2gs879 &&
+ git add ab2gs879 &&
+
+ test_tick &&
+ git commit -m ad2uee
+
+'
+
+test_expect_failure 'parse describe name taking advantage of generation' '
+ # ambiguous at the object name level, but there is only one
+ # such commit at generation 0
+ git rev-parse --verify v1.0.0-0-g000000000 &&
+
+ # likewise for generation 2 and 4
+ git rev-parse --verify v1.0.0-2-g000000000 &&
+ git rev-parse --verify v1.0.0-4-g000000000
+'
+
+# Note: because rev-parse does not even try to disambiguate based on
+# the generation number, this test currently succeeds for a wrong
+# reason. When it learns to use the generation number, the previous
+# test should succeed, and also this test should fail because the
+# describe name used in the test with generation number can name two
+# commits. Make sure that such a future enhancement does not randomly
+# pick one.
+test_expect_success 'parse describe name not ignoring ambiguity' '
+ # ambiguous at the object name level, and there are two such
+ # commits at generation 1
+ test_must_fail git rev-parse --verify v1.0.0-1-g000000000
+'
+
+test_expect_success 'ambiguous commit-ish' '
+ # Now there are many commits that begin with the
+ # common prefix, none of these should pick one at
+ # random. They all should result in ambiguity errors.
+ test_must_fail git rev-parse --verify 110282^{commit} &&
+
+ # likewise
+ test_must_fail git log 000000000..000000000 &&
+ test_must_fail git log ..000000000 &&
+ test_must_fail git log 000000000.. &&
+ test_must_fail git log 000000000...000000000 &&
+ test_must_fail git log ...000000000 &&
+ test_must_fail git log 000000000...
+'
+
+test_expect_success 'rev-parse --disambiguate' '
+ # The test creates 16 objects that share the prefix and two
+ # commits created by commit-tree in earlier tests share a
+ # different prefix.
+ git rev-parse --disambiguate=000000000 >actual &&
+ test $(wc -l <actual) = 16 &&
+ test "$(sed -e "s/^\(.........\).*/\1/" actual | sort -u)" = 000000000
+'
+
+test_done