[PATCH] for-each-ref: new 'refshort' format

[Bert Wesarg <bert.wesarg@googlemail.com>]

Here is a first sketch for this idea.

This strips from the refname the common prefix with the matched pattern.

Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>

---

I think we should use a ':short' modifier to 'reflog' and '*reflog'.

 builtin-for-each-ref.c |   39 +++++++++++++++++++++++++++++++++++++--
 1 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/builtin-for-each-ref.c b/builtin-for-each-ref.c
index 21e92bb..b80d753 100644
--- a/builtin-for-each-ref.c
+++ b/builtin-for-each-ref.c
@@ -31,6 +31,7 @@ struct ref_sort {
 
 struct refinfo {
 	char *refname;
+	const char *pattern; /* the pattern which matched this ref */
 	unsigned char objectname[20];
 	struct atom_value *value;
 };
@@ -66,6 +67,7 @@ static struct {
 	{ "subject" },
 	{ "body" },
 	{ "contents" },
+	{ "refshort" },
 };
 
 /*
@@ -546,6 +548,36 @@ static void grab_values(struct atom_value *val, int deref, struct object *obj, v
 }
 
 /*
+ * Use the matched pattern from ref to shorten the refname
+ */
+static char *get_short_ref(struct refinfo *ref)
+{
+	int rlen, plen, len = 0;
+
+	if (!ref->pattern)
+		return ref->refname;
+
+	rlen = strlen(ref->refname);
+	plen = strlen(ref->pattern);
+
+	if ((plen <= rlen) &&
+	    !strncmp(ref->refname, ref->pattern, plen) &&
+	    (ref->refname[plen] == '\0' ||
+	     ref->refname[plen] == '/' ||
+	     ref->pattern[plen - 1] == '/')) {
+		len = plen + (ref->refname[plen] == '/');
+	} else {
+		len = strcspn(ref->pattern, "*?[");
+		while (len >= 0 && ref->pattern[len] != '/')
+			--len;
+		len++;
+	}
+
+	return ref->refname + len;
+}
+
+
+/*
  * Parse the object referred by ref, and grab needed value.
  */
 static void populate_value(struct refinfo *ref)
@@ -577,6 +609,8 @@ static void populate_value(struct refinfo *ref)
 			char *s = xmalloc(len + 4);
 			sprintf(s, "%s^{}", ref->refname);
 			v->s = s;
+		} else if (!strcmp(name, "refshort")) {
+			v->s = get_short_ref(ref);
 		}
 	}
 
@@ -641,9 +675,9 @@ static int grab_single_ref(const char *refname, const unsigned char *sha1, int f
 	struct grab_ref_cbdata *cb = cb_data;
 	struct refinfo *ref;
 	int cnt;
+	const char **pattern = cb->grab_pattern;
 
-	if (*cb->grab_pattern) {
-		const char **pattern;
+	if (*pattern) {
 		int namelen = strlen(refname);
 		for (pattern = cb->grab_pattern; *pattern; pattern++) {
 			const char *p = *pattern;
@@ -668,6 +702,7 @@ static int grab_single_ref(const char *refname, const unsigned char *sha1, int f
 	 */
 	ref = xcalloc(1, sizeof(*ref));
 	ref->refname = xstrdup(refname);
+	ref->pattern = *pattern;
 	hashcpy(ref->objectname, sha1);
 
 	cnt = cb->grab_cnt;
-- 
1.6.0