[RFC/PATCH 4/9] ref-filter: add support to sort by version

[Karthik Nayak <karthik.188@gmail.com>]

Add support to sort by version using the "v:refname" and
"version:refname" option. This is achieved by using the
'version_cmp()' function as the comparing function for qsort.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
---
 ref-filter.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/ref-filter.c b/ref-filter.c
index 57a5cfb..e307fab 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -10,8 +10,9 @@
 #include "quote.h"
 #include "ref-filter.h"
 #include "revision.h"
+#include "version.h"
 
-typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
+typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME, FIELD_VER } cmp_type;
 
 static struct {
 	const char *name;
@@ -53,6 +54,8 @@ static struct {
 	{ "flag" },
 	{ "HEAD" },
 	{ "color" },
+	{ "version", FIELD_VER },
+	{ "v", FIELD_VER },
 };
 
 /*
@@ -629,7 +632,9 @@ static void populate_value(struct ref_array_item *ref)
 			name++;
 		}
 
-		if (starts_with(name, "refname"))
+		if (starts_with(name, "refname") ||
+		    starts_with(name, "version:") ||
+		    starts_with(name, "v:"))
 			refname = ref->refname;
 		else if (starts_with(name, "symref"))
 			refname = ref->symref ? ref->symref : "";
@@ -695,7 +700,13 @@ static void populate_value(struct ref_array_item *ref)
 			int num_ours, num_theirs;
 
 			formatp++;
-			if (starts_with(formatp, "lalign")) {
+			if (starts_with(name, "version") || starts_with(name, "v")) {
+				if (strcmp(formatp, "refname"))
+					die("unknown %.*s format %s",
+					    (int)(formatp - name), name, formatp);
+				v->s = refname;
+				continue;
+			} else if (starts_with(formatp, "lalign")) {
 				const char *valp;
 				int val;
 
@@ -1165,6 +1176,9 @@ static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, stru
 	case FIELD_STR:
 		cmp = strcmp(va->s, vb->s);
 		break;
+	case FIELD_VER:
+		cmp = versioncmp(va->s, vb->s);
+		break;
 	default:
 		if (va->ul < vb->ul)
 			cmp = -1;
-- 
2.4.4