1 files changed, 53 insertions, 9 deletions

diff --git a/third_party/git/refspec.c b/third_party/git/refspec.c
index 9a9bf21934..8af357a0a3 100644
--- a/third_party/git/refspec.c
+++ b/third_party/git/refspec.c
@@ -1,5 +1,5 @@
 #include "cache.h"
-#include "argv-array.h"
+#include "strvec.h"
 #include "refs.h"
 #include "refspec.h"
 
@@ -8,6 +8,7 @@ static struct refspec_item s_tag_refspec = {
 	1,
 	0,
 	0,
+	0,
 	"refs/tags/*",
 	"refs/tags/*"
 };
@@ -32,10 +33,17 @@ static int parse_refspec(struct refspec_item *item, const char *refspec, int fet
 	if (*lhs == '+') {
 		item->force = 1;
 		lhs++;
+	} else if (*lhs == '^') {
+		item->negative = 1;
+		lhs++;
 	}
 
 	rhs = strrchr(lhs, ':');
 
+	/* negative refspecs only have one side */
+	if (item->negative && rhs)
+		return 0;
+
 	/*
 	 * Before going on, special case ":" (or "+:") as a refspec
 	 * for pushing matching refs.
@@ -55,7 +63,7 @@ static int parse_refspec(struct refspec_item *item, const char *refspec, int fet
 
 	llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
 	if (1 <= llen && memchr(lhs, '*', llen)) {
-		if ((rhs && !is_glob) || (!rhs && fetch))
+		if ((rhs && !is_glob) || (!rhs && !item->negative && fetch))
 			return 0;
 		is_glob = 1;
 	} else if (rhs && is_glob) {
@@ -66,6 +74,28 @@ static int parse_refspec(struct refspec_item *item, const char *refspec, int fet
 	item->src = xstrndup(lhs, llen);
 	flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);
 
+	if (item->negative) {
+		struct object_id unused;
+
+		/*
+		 * Negative refspecs only have a LHS, which indicates a ref
+		 * (or pattern of refs) to exclude from other matches. This
+		 * can either be a simple ref, or a glob pattern. Exact sha1
+		 * match is not currently supported.
+		 */
+		if (!*item->src)
+			return 0; /* negative refspecs must not be empty */
+		else if (llen == the_hash_algo->hexsz && !get_oid_hex(item->src, &unused))
+			return 0; /* negative refpsecs cannot be exact sha1 */
+		else if (!check_refname_format(item->src, flags))
+			; /* valid looking ref is ok */
+		else
+			return 0;
+
+		/* the other rules below do not apply to negative refspecs */
+		return 1;
+	}
+
 	if (fetch) {
 		struct object_id unused;
 
@@ -153,7 +183,7 @@ void refspec_init(struct refspec *rs, int fetch)
 	rs->fetch = fetch;
 }
 
-void refspec_append(struct refspec *rs, const char *refspec)
+static void refspec_append_nodup(struct refspec *rs, char *refspec)
 {
 	struct refspec_item item;
 
@@ -163,7 +193,21 @@ void refspec_append(struct refspec *rs, const char *refspec)
 	rs->items[rs->nr++] = item;
 
 	ALLOC_GROW(rs->raw, rs->raw_nr + 1, rs->raw_alloc);
-	rs->raw[rs->raw_nr++] = xstrdup(refspec);
+	rs->raw[rs->raw_nr++] = refspec;
+}
+
+void refspec_append(struct refspec *rs, const char *refspec)
+{
+	refspec_append_nodup(rs, xstrdup(refspec));
+}
+
+void refspec_appendf(struct refspec *rs, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	refspec_append_nodup(rs, xstrvfmt(fmt, ap));
+	va_end(ap);
 }
 
 void refspec_appendn(struct refspec *rs, const char **refspecs, int nr)
@@ -202,14 +246,14 @@ int valid_fetch_refspec(const char *fetch_refspec_str)
 }
 
 void refspec_ref_prefixes(const struct refspec *rs,
-			  struct argv_array *ref_prefixes)
+			  struct strvec *ref_prefixes)
 {
 	int i;
 	for (i = 0; i < rs->nr; i++) {
 		const struct refspec_item *item = &rs->items[i];
 		const char *prefix = NULL;
 
-		if (item->exact_sha1)
+		if (item->exact_sha1 || item->negative)
 			continue;
 		if (rs->fetch == REFSPEC_FETCH)
 			prefix = item->src;
@@ -221,9 +265,9 @@ void refspec_ref_prefixes(const struct refspec *rs,
 		if (prefix) {
 			if (item->pattern) {
 				const char *glob = strchr(prefix, '*');
-				argv_array_pushf(ref_prefixes, "%.*s",
-						 (int)(glob - prefix),
-						 prefix);
+				strvec_pushf(ref_prefixes, "%.*s",
+					     (int)(glob - prefix),
+					     prefix);
 			} else {
 				expand_ref_prefix(ref_prefixes, prefix);
 			}