From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 10 Feb 2016 22:20:10 +0000 (-0800)
Subject: Merge branch 'wp/sha1-name-negative-match'
X-Git-Tag: v2.8.0-rc0~58
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/fb795323ce3ce5a358f8e55641777b9cdbeab846?ds=inline;hp=-c

Merge branch 'wp/sha1-name-negative-match'

A new "<branch>^{/!-<pattern>}" notation can be used to name a
commit that is reachable from <branch> that does not match the
given <pattern>.

* wp/sha1-name-negative-match:
object name: introduce '^{/!-<negative pattern>}' notation
test for '!' handling in rev-parse's named commits
---

fb795323ce3ce5a358f8e55641777b9cdbeab846
diff --combined Documentation/revisions.txt
index fa4bdb208c,e0cd03fba9..19314e3b7f
--- a/Documentation/revisions.txt
+++ b/Documentation/revisions.txt
@@@ -61,11 -61,11 +61,11 @@@ some output processing may assume ref n
  '@'::
    '@' alone is a shortcut for 'HEAD'.
  
 -'<refname>@\{<date>\}', e.g. 'master@\{yesterday\}', 'HEAD@\{5 minutes ago\}'::
 +'<refname>@{<date>}', e.g. 'master@\{yesterday\}', 'HEAD@{5 minutes ago}'::
    A ref followed by the suffix '@' with a date specification
    enclosed in a brace
 -  pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
 -  second ago\}' or '\{1979-02-26 18:30:00\}') specifies the value
 +  pair (e.g. '\{yesterday\}', '{1 month 2 weeks 3 days 1 hour 1
 +  second ago}' or '{1979-02-26 18:30:00}') specifies the value
    of the ref at a prior point in time.  This suffix may only be
    used immediately following a ref name and the ref must have an
    existing log ('$GIT_DIR/logs/<ref>'). Note that this looks up the state
@@@ -73,7 -73,7 +73,7 @@@
    'master' branch last week. If you want to look at commits made during
    certain times, see '--since' and '--until'.
  
 -'<refname>@\{<n>\}', e.g. 'master@\{1\}'::
 +'<refname>@{<n>}', e.g. 'master@\{1\}'::
    A ref followed by the suffix '@' with an ordinal specification
    enclosed in a brace pair (e.g. '\{1\}', '\{15\}') specifies
    the n-th prior value of that ref.  For example 'master@\{1\}'
@@@ -82,13 -82,13 +82,13 @@@
    immediately following a ref name and the ref must have an existing
    log ('$GIT_DIR/logs/<refname>').
  
 -'@\{<n>\}', e.g. '@\{1\}'::
 +'@{<n>}', e.g. '@\{1\}'::
    You can use the '@' construct with an empty ref part to get at a
    reflog entry of the current branch. For example, if you are on
    branch 'blabla' then '@\{1\}' means the same as 'blabla@\{1\}'.
  
 -'@\{-<n>\}', e.g. '@\{-1\}'::
 -  The construct '@\{-<n>\}' means the <n>th branch/commit checked out
 +'@{-<n>}', e.g. '@{-1}'::
 +  The construct '@{-<n>}' means the <n>th branch/commit checked out
    before the current one.
  
  '<branchname>@\{upstream\}', e.g. 'master@\{upstream\}', '@\{u\}'::
@@@ -98,31 -98,6 +98,31 @@@
    `branch.<name>.merge`).  A missing branchname defaults to the
    current one.
  
 +'<branchname>@\{push\}', e.g. 'master@\{push\}', '@\{push\}'::
 +  The suffix '@\{push}' reports the branch "where we would push to" if
 +  `git push` were run while `branchname` was checked out (or the current
 +  'HEAD' if no branchname is specified). Since our push destination is
 +  in a remote repository, of course, we report the local tracking branch
 +  that corresponds to that branch (i.e., something in 'refs/remotes/').
 ++
 +Here's an example to make it more clear:
 ++
 +------------------------------
 +$ git config push.default current
 +$ git config remote.pushdefault myfork
 +$ git checkout -b mybranch origin/master
 +
 +$ git rev-parse --symbolic-full-name @{upstream}
 +refs/remotes/origin/master
 +
 +$ git rev-parse --symbolic-full-name @{push}
 +refs/remotes/myfork/mybranch
 +------------------------------
 ++
 +Note in the example that we set up a triangular workflow, where we pull
 +from one location and push to another. In a non-triangular workflow,
 +'@\{push}' is the same as '@\{upstream}', and there is no need for it.
 +
  '<rev>{caret}', e.g. 'HEAD{caret}, v1.5.1{caret}0'::
    A suffix '{caret}' to a revision parameter means the first parent of
    that commit object.  '{caret}<n>' means the <n>th parent (i.e.
@@@ -139,7 -114,7 +139,7 @@@
    '<rev>{caret}1{caret}1{caret}1'.  See below for an illustration of
    the usage of this form.
  
 -'<rev>{caret}\{<type>\}', e.g. 'v0.99.8{caret}\{commit\}'::
 +'<rev>{caret}{<type>}', e.g. 'v0.99.8{caret}\{commit\}'::
    A suffix '{caret}' followed by an object type name enclosed in
    brace pair means dereference the object at '<rev>' recursively until
    an object of type '<type>' is found or the object cannot be
@@@ -159,13 -134,13 +159,13 @@@ it does not have to be dereferenced eve
  'rev{caret}\{tag\}' can be used to ensure that 'rev' identifies an
  existing tag object.
  
 -'<rev>{caret}\{\}', e.g. 'v0.99.8{caret}\{\}'::
 +'<rev>{caret}{}', e.g. 'v0.99.8{caret}{}'::
    A suffix '{caret}' followed by an empty brace pair
    means the object could be a tag,
    and dereference the tag recursively until a non-tag object is
    found.
  
 -'<rev>{caret}\{/<text>\}', e.g. 'HEAD^{/fix nasty bug}'::
 +'<rev>{caret}{/<text>}', e.g. 'HEAD^{/fix nasty bug}'::
    A suffix '{caret}' to a revision parameter, followed by a brace
    pair that contains a text led by a slash,
    is the same as the ':/fix nasty bug' syntax below except that
@@@ -176,11 -151,12 +176,12 @@@
    A colon, followed by a slash, followed by a text, names
    a commit whose commit message matches the specified regular expression.
    This name returns the youngest matching commit which is
-   reachable from any ref.  If the commit message starts with a
-   '!' you have to repeat that;  the special sequence ':/!',
-   followed by something else than '!', is reserved for now.
-   The regular expression can match any part of the commit message. To
-   match messages starting with a string, one can use e.g. ':/^foo'.
+   reachable from any ref. The regular expression can match any part of the
+   commit message. To match messages starting with a string, one can use
+   e.g. ':/^foo'. The special sequence ':/!' is reserved for modifiers to what
+   is matched. ':/!-foo' performs a negative match, while ':/!!foo' matches a
+   literal '!' character, followed by 'foo'. Any other sequence beginning with
+   ':/!' is reserved for now.
  
  '<rev>:<path>', e.g. 'HEAD:README', ':README', 'master:./README'::
    A suffix ':' followed by a path names the blob or tree
diff --combined sha1_name.c
index 892db21813,fc5c60d3f2..89918ca158
--- a/sha1_name.c
+++ b/sha1_name.c
@@@ -6,7 -6,6 +6,7 @@@
  #include "tree-walk.h"
  #include "refs.h"
  #include "remote.h"
 +#include "dir.h"
  
  static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
  
@@@ -96,15 -95,11 +96,15 @@@ static void find_short_object_filename(
  	}
  	fakeent->next = alt_odb_list;
  
 -	sprintf(hex, "%.2s", hex_pfx);
 +	xsnprintf(hex, sizeof(hex), "%.2s", hex_pfx);
  	for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
  		struct dirent *de;
  		DIR *dir;
 -		sprintf(alt->name, "%.2s/", hex_pfx);
 +		/*
 +		 * every alt_odb struct has 42 extra bytes after the base
 +		 * for exactly this purpose
 +		 */
 +		xsnprintf(alt->name, 42, "%.2s/", hex_pfx);
  		dir = opendir(alt->base);
  		if (!dir)
  			continue;
@@@ -372,13 -367,14 +372,13 @@@ int for_each_abbrev(const char *prefix
  	return ds.ambiguous;
  }
  
 -const char *find_unique_abbrev(const unsigned char *sha1, int len)
 +int find_unique_abbrev_r(char *hex, const unsigned char *sha1, int len)
  {
  	int status, exists;
 -	static char hex[41];
  
 -	memcpy(hex, sha1_to_hex(sha1), 40);
 +	sha1_to_hex_r(hex, sha1);
  	if (len == 40 || !len)
 -		return hex;
 +		return 40;
  	exists = has_sha1_file(sha1);
  	while (len < 40) {
  		unsigned char sha1_ret[20];
@@@ -387,17 -383,10 +387,17 @@@
  		    ? !status
  		    : status == SHORT_NAME_NOT_FOUND) {
  			hex[len] = 0;
 -			return hex;
 +			return len;
  		}
  		len++;
  	}
 +	return len;
 +}
 +
 +const char *find_unique_abbrev(const unsigned char *sha1, int len)
 +{
 +	static char hex[GIT_SHA1_HEXSZ + 1];
 +	find_unique_abbrev_r(hex, sha1, len);
  	return hex;
  }
  
@@@ -426,12 -415,12 +426,12 @@@ static int ambiguous_path(const char *p
  	return slash;
  }
  
 -static inline int upstream_mark(const char *string, int len)
 +static inline int at_mark(const char *string, int len,
 +			  const char **suffix, int nr)
  {
 -	const char *suffix[] = { "@{upstream}", "@{u}" };
  	int i;
  
 -	for (i = 0; i < ARRAY_SIZE(suffix); i++) {
 +	for (i = 0; i < nr; i++) {
  		int suffix_len = strlen(suffix[i]);
  		if (suffix_len <= len
  		    && !memcmp(string, suffix[i], suffix_len))
@@@ -440,18 -429,6 +440,18 @@@
  	return 0;
  }
  
 +static inline int upstream_mark(const char *string, int len)
 +{
 +	const char *suffix[] = { "@{upstream}", "@{u}" };
 +	return at_mark(string, len, suffix, ARRAY_SIZE(suffix));
 +}
 +
 +static inline int push_mark(const char *string, int len)
 +{
 +	const char *suffix[] = { "@{push}" };
 +	return at_mark(string, len, suffix, ARRAY_SIZE(suffix));
 +}
 +
  static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
  static int interpret_nth_prior_checkout(const char *name, int namelen, struct strbuf *buf);
  
@@@ -499,8 -476,7 +499,8 @@@ static int get_sha1_basic(const char *s
  					nth_prior = 1;
  					continue;
  				}
 -				if (!upstream_mark(str + at, len - at)) {
 +				if (!upstream_mark(str + at, len - at) &&
 +				    !push_mark(str + at, len - at)) {
  					reflog_len = (len-1) - (at+2);
  					len = at;
  				}
@@@ -586,7 -562,7 +586,7 @@@
  				if (!(flags & GET_SHA1_QUIETLY)) {
  					warning("Log for '%.*s' only goes "
  						"back to %s.", len, str,
 -						show_date(co_time, co_tz, DATE_RFC2822));
 +						show_date(co_time, co_tz, DATE_MODE(RFC2822)));
  				}
  			} else {
  				if (flags & GET_SHA1_QUIETLY) {
@@@ -616,13 -592,13 +616,13 @@@ static int get_parent(const char *name
  	if (parse_commit(commit))
  		return -1;
  	if (!idx) {
 -		hashcpy(result, commit->object.sha1);
 +		hashcpy(result, commit->object.oid.hash);
  		return 0;
  	}
  	p = commit->parents;
  	while (p) {
  		if (!--idx) {
 -			hashcpy(result, p->item->object.sha1);
 +			hashcpy(result, p->item->object.oid.hash);
  			return 0;
  		}
  		p = p->next;
@@@ -649,7 -625,7 +649,7 @@@ static int get_nth_ancestor(const char 
  			return -1;
  		commit = commit->parents->item;
  	}
 -	hashcpy(result, commit->object.sha1);
 +	hashcpy(result, commit->object.oid.hash);
  	return 0;
  }
  
@@@ -659,7 -635,7 +659,7 @@@ struct object *peel_to_type(const char 
  	if (name && !namelen)
  		namelen = strlen(name);
  	while (1) {
 -		if (!o || (!o->parsed && !parse_object(o->sha1)))
 +		if (!o || (!o->parsed && !parse_object(o->oid.hash)))
  			return NULL;
  		if (expected_type == OBJ_ANY || o->type == expected_type)
  			return o;
@@@ -736,9 -712,9 +736,9 @@@ static int peel_onion(const char *name
  		return -1;
  	if (!expected_type) {
  		o = deref_tag(o, name, sp - name - 2);
 -		if (!o || (!o->parsed && !parse_object(o->sha1)))
 +		if (!o || (!o->parsed && !parse_object(o->oid.hash)))
  			return -1;
 -		hashcpy(sha1, o->sha1);
 +		hashcpy(sha1, o->oid.hash);
  		return 0;
  	}
  
@@@ -751,7 -727,7 +751,7 @@@
  	if (!o)
  		return -1;
  
 -	hashcpy(sha1, o->sha1);
 +	hashcpy(sha1, o->oid.hash);
  	if (sp[0] == '/') {
  		/* "$commit^{/foo}" */
  		char *prefix;
@@@ -848,18 -824,22 +848,22 @@@ static int get_sha1_1(const char *name
   * through history and returning the first commit whose message starts
   * the given regular expression.
   *
-  * For future extension, ':/!' is reserved. If you want to match a message
-  * beginning with a '!', you have to repeat the exclamation mark.
+  * For negative-matching, prefix the pattern-part with '!-', like: ':/!-WIP'.
+  *
+  * For a literal '!' character at the beginning of a pattern, you have to repeat
+  * that, like: ':/!!foo'
+  *
+  * For future extension, all other sequences beginning with ':/!' are reserved.
   */
  
  /* Remember to update object flag allocation in object.h */
  #define ONELINE_SEEN (1u<<20)
  
 -static int handle_one_ref(const char *path,
 -		const unsigned char *sha1, int flag, void *cb_data)
 +static int handle_one_ref(const char *path, const struct object_id *oid,
 +			  int flag, void *cb_data)
  {
  	struct commit_list **list = cb_data;
 -	struct object *object = parse_object(sha1);
 +	struct object *object = parse_object(oid->hash);
  	if (!object)
  		return 0;
  	if (object->type == OBJ_TAG) {
@@@ -878,12 -858,18 +882,18 @@@ static int get_sha1_oneline(const char 
  {
  	struct commit_list *backup = NULL, *l;
  	int found = 0;
+ 	int negative = 0;
  	regex_t regex;
  
  	if (prefix[0] == '!') {
- 		if (prefix[1] != '!')
- 			die ("Invalid search pattern: %s", prefix);
  		prefix++;
+ 
+ 		if (prefix[0] == '-') {
+ 			prefix++;
+ 			negative = 1;
+ 		} else if (prefix[0] != '!') {
+ 			die ("Invalid search pattern: %s", prefix);
+ 		}
  	}
  
  	if (regcomp(&regex, prefix, REG_EXTENDED))
@@@ -899,15 -885,15 +909,15 @@@
  		int matches;
  
  		commit = pop_most_recent_commit(&list, ONELINE_SEEN);
 -		if (!parse_object(commit->object.sha1))
 +		if (!parse_object(commit->object.oid.hash))
  			continue;
  		buf = get_commit_buffer(commit, NULL);
  		p = strstr(buf, "\n\n");
- 		matches = p && !regexec(&regex, p + 2, 0, NULL, 0);
+ 		matches = negative ^ (p && !regexec(&regex, p + 2, 0, NULL, 0));
  		unuse_commit_buffer(commit, buf);
  
  		if (matches) {
 -			hashcpy(sha1, commit->object.sha1);
 +			hashcpy(sha1, commit->object.oid.hash);
  			found = 1;
  			break;
  		}
@@@ -1022,7 -1008,7 +1032,7 @@@ int get_sha1_mb(const char *name, unsig
  		st = -1;
  	else {
  		st = 0;
 -		hashcpy(sha1, mbs->item->object.sha1);
 +		hashcpy(sha1, mbs->item->object.oid.hash);
  	}
  	free_commit_list(mbs);
  	return st;
@@@ -1079,36 -1065,46 +1089,36 @@@ static void set_shortened_ref(struct st
  	free(s);
  }
  
 -static const char *get_upstream_branch(const char *branch_buf, int len)
 -{
 -	char *branch = xstrndup(branch_buf, len);
 -	struct branch *upstream = branch_get(*branch ? branch : NULL);
 -
 -	/*
 -	 * Upstream can be NULL only if branch refers to HEAD and HEAD
 -	 * points to something different than a branch.
 -	 */
 -	if (!upstream)
 -		die(_("HEAD does not point to a branch"));
 -	if (!upstream->merge || !upstream->merge[0]->dst) {
 -		if (!ref_exists(upstream->refname))
 -			die(_("No such branch: '%s'"), branch);
 -		if (!upstream->merge) {
 -			die(_("No upstream configured for branch '%s'"),
 -				upstream->name);
 -		}
 -		die(
 -			_("Upstream branch '%s' not stored as a remote-tracking branch"),
 -			upstream->merge[0]->src);
 -	}
 -	free(branch);
 -
 -	return upstream->merge[0]->dst;
 -}
 -
 -static int interpret_upstream_mark(const char *name, int namelen,
 -				   int at, struct strbuf *buf)
 +static int interpret_branch_mark(const char *name, int namelen,
 +				 int at, struct strbuf *buf,
 +				 int (*get_mark)(const char *, int),
 +				 const char *(*get_data)(struct branch *,
 +							 struct strbuf *))
  {
  	int len;
 +	struct branch *branch;
 +	struct strbuf err = STRBUF_INIT;
 +	const char *value;
  
 -	len = upstream_mark(name + at, namelen - at);
 +	len = get_mark(name + at, namelen - at);
  	if (!len)
  		return -1;
  
  	if (memchr(name, ':', at))
  		return -1;
  
 -	set_shortened_ref(buf, get_upstream_branch(name, at));
 +	if (at) {
 +		char *name_str = xmemdupz(name, at);
 +		branch = branch_get(name_str);
 +		free(name_str);
 +	} else
 +		branch = branch_get(NULL);
 +
 +	value = get_data(branch, &err);
 +	if (!value)
 +		die("%s", err.buf);
 +
 +	set_shortened_ref(buf, value);
  	return len + at;
  }
  
@@@ -1159,13 -1155,7 +1169,13 @@@ int interpret_branch_name(const char *n
  		if (len > 0)
  			return reinterpret(name, namelen, len, buf);
  
 -		len = interpret_upstream_mark(name, namelen, at - name, buf);
 +		len = interpret_branch_mark(name, namelen, at - name, buf,
 +					    upstream_mark, branch_get_upstream);
 +		if (len > 0)
 +			return len;
 +
 +		len = interpret_branch_mark(name, namelen, at - name, buf,
 +					    push_mark, branch_get_push);
  		if (len > 0)
  			return len;
  	}
@@@ -1257,13 -1247,14 +1267,13 @@@ static void diagnose_invalid_sha1_path(
  				       const char *object_name,
  				       int object_name_len)
  {
 -	struct stat st;
  	unsigned char sha1[20];
  	unsigned mode;
  
  	if (!prefix)
  		prefix = "";
  
 -	if (!lstat(filename, &st))
 +	if (file_exists(filename))
  		die("Path '%s' exists on disk, but not in '%.*s'.",
  		    filename, object_name_len, object_name);
  	if (errno == ENOENT || errno == ENOTDIR) {
@@@ -1290,10 -1281,12 +1300,10 @@@ static void diagnose_invalid_index_path
  					const char *prefix,
  					const char *filename)
  {
 -	struct stat st;
  	const struct cache_entry *ce;
  	int pos;
  	unsigned namelen = strlen(filename);
 -	unsigned fullnamelen;
 -	char *fullname;
 +	struct strbuf fullname = STRBUF_INIT;
  
  	if (!prefix)
  		prefix = "";
@@@ -1313,29 -1306,31 +1323,29 @@@
  	}
  
  	/* Confusion between relative and absolute filenames? */
 -	fullnamelen = namelen + strlen(prefix);
 -	fullname = xmalloc(fullnamelen + 1);
 -	strcpy(fullname, prefix);
 -	strcat(fullname, filename);
 -	pos = cache_name_pos(fullname, fullnamelen);
 +	strbuf_addstr(&fullname, prefix);
 +	strbuf_addstr(&fullname, filename);
 +	pos = cache_name_pos(fullname.buf, fullname.len);
  	if (pos < 0)
  		pos = -pos - 1;
  	if (pos < active_nr) {
  		ce = active_cache[pos];
 -		if (ce_namelen(ce) == fullnamelen &&
 -		    !memcmp(ce->name, fullname, fullnamelen))
 +		if (ce_namelen(ce) == fullname.len &&
 +		    !memcmp(ce->name, fullname.buf, fullname.len))
  			die("Path '%s' is in the index, but not '%s'.\n"
  			    "Did you mean ':%d:%s' aka ':%d:./%s'?",
 -			    fullname, filename,
 -			    ce_stage(ce), fullname,
 +			    fullname.buf, filename,
 +			    ce_stage(ce), fullname.buf,
  			    ce_stage(ce), filename);
  	}
  
 -	if (!lstat(filename, &st))
 +	if (file_exists(filename))
  		die("Path '%s' exists on disk, but not in the index.", filename);
  	if (errno == ENOENT || errno == ENOTDIR)
  		die("Path '%s' does not exist (neither on disk nor in the index).",
  		    filename);
  
 -	free(fullname);
 +	strbuf_release(&fullname);
  }
  
  
@@@ -1386,7 -1381,6 +1396,7 @@@ static int get_sha1_with_context_1(cons
  		int pos;
  		if (!only_to_die && namelen > 2 && name[1] == '/') {
  			struct commit_list *list = NULL;
 +
  			for_each_ref(handle_one_ref, &list);
  			commit_list_sort_by_date(&list);
  			return get_sha1_oneline(name + 2, sha1, list);
@@@ -1450,19 -1444,11 +1460,19 @@@
  			new_filename = resolve_relative_path(filename);
  			if (new_filename)
  				filename = new_filename;
 -			ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
 -			if (ret && only_to_die) {
 -				diagnose_invalid_sha1_path(prefix, filename,
 -							   tree_sha1,
 -							   name, len);
 +			if (flags & GET_SHA1_FOLLOW_SYMLINKS) {
 +				ret = get_tree_entry_follow_symlinks(tree_sha1,
 +					filename, sha1, &oc->symlink_path,
 +					&oc->mode);
 +			} else {
 +				ret = get_tree_entry(tree_sha1, filename,
 +						     sha1, &oc->mode);
 +				if (ret && only_to_die) {
 +					diagnose_invalid_sha1_path(prefix,
 +								   filename,
 +								   tree_sha1,
 +								   name, len);
 +				}
  			}
  			hashcpy(oc->tree, tree_sha1);
  			strlcpy(oc->path, filename, sizeof(oc->path));
@@@ -1493,7 -1479,5 +1503,7 @@@ void maybe_die_on_misspelt_object_name(
  
  int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
  {
 +	if (flags & GET_SHA1_FOLLOW_SYMLINKS && flags & GET_SHA1_ONLY_TO_DIE)
 +		die("BUG: incompatible flags for get_sha1_with_context");
  	return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
  }
diff --combined t/t1511-rev-parse-caret.sh
index 7043ba7947,8a5983fcd2..e0a49a651f
--- a/t/t1511-rev-parse-caret.sh
+++ b/t/t1511-rev-parse-caret.sh
@@@ -6,11 -6,11 +6,11 @@@ test_description='tests for ref^{stuff}
  
  test_expect_success 'setup' '
  	echo blob >a-blob &&
 -	git tag -a -m blob blob-tag `git hash-object -w a-blob` &&
 +	git tag -a -m blob blob-tag $(git hash-object -w a-blob) &&
  	mkdir a-tree &&
  	echo moreblobs >a-tree/another-blob &&
  	git add . &&
 -	TREE_SHA1=`git write-tree` &&
 +	TREE_SHA1=$(git write-tree) &&
  	git tag -a -m tree tree-tag "$TREE_SHA1" &&
  	git commit -m Initial &&
  	git tag -a -m commit commit-tag &&
@@@ -18,7 -18,18 +18,18 @@@
  	git checkout master &&
  	echo modified >>a-blob &&
  	git add -u &&
- 	git commit -m Modified
+ 	git commit -m Modified &&
+ 	git branch modref &&
+ 	echo changed! >>a-blob &&
+ 	git add -u &&
+ 	git commit -m !Exp &&
+ 	git branch expref &&
+ 	echo changed >>a-blob &&
+ 	git add -u &&
+ 	git commit -m Changed &&
+ 	echo changed-again >>a-blob &&
+ 	git add -u &&
+ 	git commit -m Changed-again
  '
  
  test_expect_success 'ref^{non-existent}' '
@@@ -77,4 -88,44 +88,44 @@@ test_expect_success 'ref^{/Initial}' 
  	test_cmp expected actual
  '
  
+ test_expect_success 'ref^{/!Exp}' '
+ 	test_must_fail git rev-parse master^{/!Exp}
+ '
+ 
+ test_expect_success 'ref^{/!}' '
+ 	test_must_fail git rev-parse master^{/!}
+ '
+ 
+ test_expect_success 'ref^{/!!Exp}' '
+ 	git rev-parse expref >expected &&
+ 	git rev-parse master^{/!!Exp} >actual &&
+ 	test_cmp expected actual
+ '
+ 
+ test_expect_success 'ref^{/!-}' '
+ 	test_must_fail git rev-parse master^{/!-}
+ '
+ 
+ test_expect_success 'ref^{/!-.}' '
+ 	test_must_fail git rev-parse master^{/!-.}
+ '
+ 
+ test_expect_success 'ref^{/!-non-existent}' '
+ 	git rev-parse master >expected &&
+ 	git rev-parse master^{/!-non-existent} >actual &&
+ 	test_cmp expected actual
+ '
+ 
+ test_expect_success 'ref^{/!-Changed}' '
+ 	git rev-parse expref >expected &&
+ 	git rev-parse master^{/!-Changed} >actual &&
+ 	test_cmp expected actual
+ '
+ 
+ test_expect_success 'ref^{/!-!Exp}' '
+ 	git rev-parse modref >expected &&
+ 	git rev-parse expref^{/!-!Exp} >actual &&
+ 	test_cmp expected actual
+ '
+ 
  test_done