for_each_string_list_item: avoid undefined behavior for empty list

diff --git a/builtin/describe.c b/builtin/describe.c
index a5cd8c513f96baaaa0d9a310e2bf02b8db41199b..89ea1cdd60a215473ecb52ff2a4ce51932e1cf6d 100644 (file)
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "config.h"
 #include "lockfile.h"
 #include "commit.h"
 #include "tag.h"
@@ -53,8 +54,10 @@ static const char *prio_names[] = {
        N_("head"), N_("lightweight"), N_("annotated"),
 };
 
-static int commit_name_cmp(const struct commit_name *cn1,
-               const struct commit_name *cn2, const void *peeled)
+static int commit_name_cmp(const void *unused_cmp_data,
+                          const struct commit_name *cn1,
+                          const struct commit_name *cn2,
+                          const void *peeled)
 {
        return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
 }
@@ -79,13 +82,13 @@ static int replace_name(struct commit_name *e,
                struct tag *t;
 
                if (!e->tag) {
-                       t = lookup_tag(e->oid.hash);
+                       t = lookup_tag(&e->oid);
                        if (!t || parse_tag(t))
                                return 1;
                        e->tag = t;
                }
 
-               t = lookup_tag(oid->hash);
+               t = lookup_tag(oid);
                if (!t || parse_tag(t))
                        return 0;
                *tag = t;
@@ -142,7 +145,7 @@ static int get_name(const char *path, const struct object_id *oid, int flag, voi
                        return 0;
 
                for_each_string_list_item(item, &exclude_patterns) {
-                       if (!wildmatch(item->string, path + 10, 0, NULL))
+                       if (!wildmatch(item->string, path + 10, 0))
                                return 0;
                }
        }
@@ -158,7 +161,7 @@ static int get_name(const char *path, const struct object_id *oid, int flag, voi
                        return 0;
 
                for_each_string_list_item(item, &patterns) {
-                       if (!wildmatch(item->string, path + 10, 0, NULL))
+                       if (!wildmatch(item->string, path + 10, 0))
                                break;
 
                        /* If we get here, no pattern matched. */
@@ -245,7 +248,7 @@ static unsigned long finish_depth_computation(
 static void display_name(struct commit_name *n)
 {
        if (n->prio == 2 && !n->tag) {
-               n->tag = lookup_tag(n->oid.hash);
+               n->tag = lookup_tag(&n->oid);
                if (!n->tag || parse_tag(n->tag))
                        die(_("annotated tag %s not available"), n->path);
        }
@@ -281,7 +284,7 @@ static void describe(const char *arg, int last_one)
 
        if (get_oid(arg, &oid))
                die(_("Not a valid object name %s"), arg);
-       cmit = lookup_commit_reference(oid.hash);
+       cmit = lookup_commit_reference(&oid);
        if (!cmit)
                die(_("%s is not a valid '%s' object"), arg, commit_type);
 
@@ -309,7 +312,7 @@ static void describe(const char *arg, int last_one)
                struct commit *c;
                struct commit_name *n = hashmap_iter_first(&names, &iter);
                for (; n; n = hashmap_iter_next(&iter)) {
-                       c = lookup_commit_reference_gently(n->peeled.hash, 1);
+                       c = lookup_commit_reference_gently(&n->peeled, 1);
                        if (c)
                                c->util = n;
                }
@@ -500,7 +503,7 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
                return cmd_name_rev(args.argc, args.argv, prefix);
        }
 
-       hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, 0);
+       hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, NULL, 0);
        for_each_rawref(get_name, NULL);
        if (!names.size && !always)
                die(_("No names found, cannot describe anything."));