path.c: clarify trie_find()'s in-code comment

[thirdparty/git.git] / refs.c

diff --git a/refs.c b/refs.c
index 92d1f6dbdd0d313cdf109e02f31a51bb55cfc601..cd297ee4bdbe48b04696ddf923273a857ce59884 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -63,7 +63,7 @@ static unsigned char refname_disposition[256] = {
  * not legal.  It is legal if it is something reasonable to have under
  * ".git/refs/"; We do not like it if:
  *
- * - any path component of it begins with ".", or
+ * - it begins with ".", or
  * - it has double dots "..", or
  * - it has ASCII control characters, or
  * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
@@ -71,31 +71,63 @@ static unsigned char refname_disposition[256] = {
  * - it ends with a "/", or
  * - it ends with ".lock", or
  * - it contains a "@{" portion
+ *
+ * When sanitized is not NULL, instead of rejecting the input refname
+ * as an error, try to come up with a usable replacement for the input
+ * refname in it.
  */
-static int check_refname_component(const char *refname, int *flags)
+static int check_refname_component(const char *refname, int *flags,
+                                  struct strbuf *sanitized)
 {
        const char *cp;
        char last = '\0';
+       size_t component_start = 0; /* garbage - not a reasonable initial value */
+
+       if (sanitized)
+               component_start = sanitized->len;
 
        for (cp = refname; ; cp++) {
                int ch = *cp & 255;
                unsigned char disp = refname_disposition[ch];
+
+               if (sanitized && disp != 1)
+                       strbuf_addch(sanitized, ch);
+
                switch (disp) {
                case 1:
                        goto out;
                case 2:
-                       if (last == '.')
-                               return -1; /* Refname contains "..". */
+                       if (last == '.') { /* Refname contains "..". */
+                               if (sanitized)
+                                       /* collapse ".." to single "." */
+                                       strbuf_setlen(sanitized, sanitized->len - 1);
+                               else
+                                       return -1;
+                       }
                        break;
                case 3:
-                       if (last == '@')
-                               return -1; /* Refname contains "@{". */
+                       if (last == '@') { /* Refname contains "@{". */
+                               if (sanitized)
+                                       sanitized->buf[sanitized->len-1] = '-';
+                               else
+                                       return -1;
+                       }
                        break;
                case 4:
-                       return -1;
+                       /* forbidden char */
+                       if (sanitized)
+                               sanitized->buf[sanitized->len-1] = '-';
+                       else
+                               return -1;
+                       break;
                case 5:
-                       if (!(*flags & REFNAME_REFSPEC_PATTERN))
-                               return -1; /* refspec can't be a pattern */
+                       if (!(*flags & REFNAME_REFSPEC_PATTERN)) {
+                               /* refspec can't be a pattern */
+                               if (sanitized)
+                                       sanitized->buf[sanitized->len-1] = '-';
+                               else
+                                       return -1;
+                       }
 
                        /*
                         * Unset the pattern flag so that we only accept
@@ -109,26 +141,48 @@ static int check_refname_component(const char *refname, int *flags)
 out:
        if (cp == refname)
                return 0; /* Component has zero length. */
-       if (refname[0] == '.')
-               return -1; /* Component starts with '.'. */
+
+       if (refname[0] == '.') { /* Component starts with '.'. */
+               if (sanitized)
+                       sanitized->buf[component_start] = '-';
+               else
+                       return -1;
+       }
        if (cp - refname >= LOCK_SUFFIX_LEN &&
-           !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
-               return -1; /* Refname ends with ".lock". */
+           !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) {
+               if (!sanitized)
+                       return -1;
+               /* Refname ends with ".lock". */
+               while (strbuf_strip_suffix(sanitized, LOCK_SUFFIX)) {
+                       /* try again in case we have .lock.lock */
+               }
+       }
        return cp - refname;
 }
 
-int check_refname_format(const char *refname, int flags)
+static int check_or_sanitize_refname(const char *refname, int flags,
+                                    struct strbuf *sanitized)
 {
        int component_len, component_count = 0;
 
-       if (!strcmp(refname, "@"))
+       if (!strcmp(refname, "@")) {
                /* Refname is a single character '@'. */
-               return -1;
+               if (sanitized)
+                       strbuf_addch(sanitized, '-');
+               else
+                       return -1;
+       }
 
        while (1) {
+               if (sanitized && sanitized->len)
+                       strbuf_complete(sanitized, '/');
+
                /* We are at the start of a path component. */
-               component_len = check_refname_component(refname, &flags);
-               if (component_len <= 0)
+               component_len = check_refname_component(refname, &flags,
+                                                       sanitized);
+               if (sanitized && component_len == 0)
+                       ; /* OK, omit empty component */
+               else if (component_len <= 0)
                        return -1;
 
                component_count++;
@@ -138,13 +192,29 @@ int check_refname_format(const char *refname, int flags)
                refname += component_len + 1;
        }
 
-       if (refname[component_len - 1] == '.')
-               return -1; /* Refname ends with '.'. */
+       if (refname[component_len - 1] == '.') {
+               /* Refname ends with '.'. */
+               if (sanitized)
+                       ; /* omit ending dot */
+               else
+                       return -1;
+       }
        if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
                return -1; /* Refname has only one component. */
        return 0;
 }
 
+int check_refname_format(const char *refname, int flags)
+{
+       return check_or_sanitize_refname(refname, flags, NULL);
+}
+
+void sanitize_refname_component(const char *refname, struct strbuf *out)
+{
+       if (check_or_sanitize_refname(refname, REFNAME_ALLOW_ONELEVEL, out))
+               BUG("sanitizing refname '%s' check returned error", refname);
+}
+
 int refname_is_safe(const char *refname)
 {
        const char *rest;
@@ -309,7 +379,7 @@ static int filter_refs(const char *refname, const struct object_id *oid,
 
 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
 {
-       struct object *o = lookup_unknown_object(name->hash);
+       struct object *o = lookup_unknown_object(name);
 
        if (o->type == OBJ_NONE) {
                int type = oid_object_info(the_repository, name, NULL);