Update git-add.txt according to the new possibilities of 'git add -p'.

[git.git] / refs.c

diff --git a/refs.c b/refs.c
index 9ccaf40172ee17472b4e33e9bd7f6dbac991d4bf..82afb8768473f605bdbce17698b219484890f4f9 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -1657,3 +1657,102 @@ struct ref *find_ref_by_name(const struct ref *list, const char *name)
                        return (struct ref *)list;
        return NULL;
 }
+
+/*
+ * generate a format suitable for scanf from a ref_rev_parse_rules
+ * rule, that is replace the "%.*s" spec with a "%s" spec
+ */
+static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
+{
+       char *spec;
+
+       spec = strstr(rule, "%.*s");
+       if (!spec || strstr(spec + 4, "%.*s"))
+               die("invalid rule in ref_rev_parse_rules: %s", rule);
+
+       /* copy all until spec */
+       strncpy(scanf_fmt, rule, spec - rule);
+       scanf_fmt[spec - rule] = '\0';
+       /* copy new spec */
+       strcat(scanf_fmt, "%s");
+       /* copy remaining rule */
+       strcat(scanf_fmt, spec + 4);
+
+       return;
+}
+
+char *shorten_unambiguous_ref(const char *ref)
+{
+       int i;
+       static char **scanf_fmts;
+       static int nr_rules;
+       char *short_name;
+
+       /* pre generate scanf formats from ref_rev_parse_rules[] */
+       if (!nr_rules) {
+               size_t total_len = 0;
+
+               /* the rule list is NULL terminated, count them first */
+               for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
+                       /* no +1 because strlen("%s") < strlen("%.*s") */
+                       total_len += strlen(ref_rev_parse_rules[nr_rules]);
+
+               scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
+
+               total_len = 0;
+               for (i = 0; i < nr_rules; i++) {
+                       scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
+                                       + total_len;
+                       gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
+                       total_len += strlen(ref_rev_parse_rules[i]);
+               }
+       }
+
+       /* bail out if there are no rules */
+       if (!nr_rules)
+               return xstrdup(ref);
+
+       /* buffer for scanf result, at most ref must fit */
+       short_name = xstrdup(ref);
+
+       /* skip first rule, it will always match */
+       for (i = nr_rules - 1; i > 0 ; --i) {
+               int j;
+               int short_name_len;
+
+               if (1 != sscanf(ref, scanf_fmts[i], short_name))
+                       continue;
+
+               short_name_len = strlen(short_name);
+
+               /*
+                * check if the short name resolves to a valid ref,
+                * but use only rules prior to the matched one
+                */
+               for (j = 0; j < i; j++) {
+                       const char *rule = ref_rev_parse_rules[j];
+                       unsigned char short_objectname[20];
+                       char refname[PATH_MAX];
+
+                       /*
+                        * the short name is ambiguous, if it resolves
+                        * (with this previous rule) to a valid ref
+                        * read_ref() returns 0 on success
+                        */
+                       mksnpath(refname, sizeof(refname),
+                                rule, short_name_len, short_name);
+                       if (!read_ref(refname, short_objectname))
+                               break;
+               }
+
+               /*
+                * short name is non-ambiguous if all previous rules
+                * haven't resolved to a valid ref
+                */
+               if (j == i)
+                       return short_name;
+       }
+
+       free(short_name);
+       return xstrdup(ref);
+}