[PATCH v4] refs: loosen restrictions on wildcard '*' refspecs

[PATCH v4] refs: loosen restrictions on wildcard '*' refspecs

[Jacob Keller]

From: Jacob Keller <jacob.keller@gmail.com>

Update the check_refname_component logic in order to allow for a less
strict refspec format in regards to REFNAME_REFSPEC_PATTERN. Previously
the '*' could only replace a single full component, and could not
replace arbitrary text. Now, refs such as `foo/bar*:foo/bar*` will be
accepted. This allows for somewhat more flexibility in references and
does not break any current users. The ref matching code already allows
this but the check_refname_format did not. Note this does also allow
refs such as `foo/bar*:foe/baz*`, that is, arbitrary renames. This was
already possible with namespace sections before, but now is possible
even as part of the pattern section. Since users have to explicitly type
these into the configuration it does not seem an issue.

Also streamline the code by making this new check part of
check_refname_component instead of checking after we error during
check_refname_format, which fits better with how other issues in refname
components are checked.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Cc: Daniel Barkalow <barkalow@iabervon.iabervon.org>
Cc: Junio C Hamano <gitster@pobox.com>
---

* Changed since v3
- updated the description of 5 in refs.c as suggested by David Turner

 Documentation/git-check-ref-format.txt |  4 ++--
 refs.c                                 | 39 +++++++++++++++++++---------------
 refs.h                                 |  4 ++--
 t/t1402-check-ref-format.sh            |  8 ++++---
 4 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/Documentation/git-check-ref-format.txt b/Documentation/git-check-ref-format.txt
index fc02959ba4ab..9044dfaadae1 100644
--- a/Documentation/git-check-ref-format.txt
+++ b/Documentation/git-check-ref-format.txt
@@ -94,8 +94,8 @@ OPTIONS
 	Interpret <refname> as a reference name pattern for a refspec
 	(as used with remote repositories).  If this option is
 	enabled, <refname> is allowed to contain a single `*`
-	in place of a one full pathname component (e.g.,
-	`foo/*/bar` but not `foo/bar*`).
+	in the refspec (e.g., `foo/bar*/baz` or `foo/bar*baz/`
+	but not `foo/bar*/baz*`).
 
 --normalize::
 	Normalize 'refname' by removing any leading slash (`/`)
diff --git a/refs.c b/refs.c
index ce8cd8d45001..a65f16fedaa0 100644
--- a/refs.c
+++ b/refs.c
@@ -20,11 +20,12 @@ struct ref_lock {
  * 2: ., look for a preceding . to reject .. in refs
  * 3: {, look for a preceding @ to reject @{ in refs
  * 4: A bad character: ASCII control characters, "~", "^", ":" or SP
+ * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
  */
 static unsigned char refname_disposition[256] = {
 	1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
 	4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
-	4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1,
+	4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
@@ -71,11 +72,13 @@ static unsigned char refname_disposition[256] = {
  * - any path component of it begins with ".", or
  * - it has double dots "..", or
  * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
- * - it ends with a "/".
- * - it ends with ".lock"
- * - it contains a "\" (backslash)
+ * - it ends with a "/", or
+ * - it ends with ".lock", or
+ * - it contains a "\" (backslash), or
+ * - it contains a "@{" portion, or
+ * - it contains a '*' unless REFNAME_REFSPEC_PATTERN is set
  */
-static int check_refname_component(const char *refname, int flags)
+static int check_refname_component(const char *refname, int *flags)
 {
 	const char *cp;
 	char last = '\0';
@@ -96,6 +99,16 @@ static int check_refname_component(const char *refname, int flags)
 			break;
 		case 4:
 			return -1;
+		case 5:
+			if (!(*flags & REFNAME_REFSPEC_PATTERN))
+				return -1; /* refspec can't be a pattern */
+
+			/*
+			 * Unset the pattern flag so that we only accept a single glob for
+			 * the entire refspec.
+			 */
+			*flags &= ~ REFNAME_REFSPEC_PATTERN;
+			break;
 		}
 		last = ch;
 	}
@@ -120,18 +133,10 @@ int check_refname_format(const char *refname, int flags)
 
 	while (1) {
 		/* We are at the start of a path component. */
-		component_len = check_refname_component(refname, flags);
-		if (component_len <= 0) {
-			if ((flags & REFNAME_REFSPEC_PATTERN) &&
-					refname[0] == '*' &&
-					(refname[1] == '\0' || refname[1] == '/')) {
-				/* Accept one wildcard as a full refname component. */
-				flags &= ~REFNAME_REFSPEC_PATTERN;
-				component_len = 1;
-			} else {
-				return -1;
-			}
-		}
+		component_len = check_refname_component(refname, &flags);
+		if (component_len <= 0)
+			return -1;
+
 		component_count++;
 		if (refname[component_len] == '\0')
 			break;
diff --git a/refs.h b/refs.h
index e82fca51f501..1809a1d57577 100644
--- a/refs.h
+++ b/refs.h
@@ -278,8 +278,8 @@ extern int for_each_reflog(each_ref_fn, void *);
  * to the rules described in Documentation/git-check-ref-format.txt.
  * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
  * reference names.  If REFNAME_REFSPEC_PATTERN is set in flags, then
- * allow a "*" wildcard character in place of one of the name
- * components.  No leading or repeated slashes are accepted.
+ * allow a single "*" wildcard character in the refspec. No leading or
+ * repeated slashes are accepted.
  */
 extern int check_refname_format(const char *refname, int flags);
 
diff --git a/t/t1402-check-ref-format.sh b/t/t1402-check-ref-format.sh
index e5dc62e9efbf..0790edf60de2 100755
--- a/t/t1402-check-ref-format.sh
+++ b/t/t1402-check-ref-format.sh
@@ -62,9 +62,11 @@ invalid_ref 'heads/foo\bar'
 invalid_ref "$(printf 'heads/foo\t')"
 invalid_ref "$(printf 'heads/foo\177')"
 valid_ref "$(printf 'heads/fu\303\237')"
-invalid_ref 'heads/*foo/bar' --refspec-pattern
-invalid_ref 'heads/foo*/bar' --refspec-pattern
-invalid_ref 'heads/f*o/bar' --refspec-pattern
+valid_ref 'heads/*foo/bar' --refspec-pattern
+valid_ref 'heads/foo*/bar' --refspec-pattern
+valid_ref 'heads/f*o/bar' --refspec-pattern
+invalid_ref 'heads/f*o*/bar' --refspec-pattern
+invalid_ref 'heads/foo*/bar*' --refspec-pattern
 
 ref='foo'
 invalid_ref "$ref"
-- 
2.4.3

Re: [PATCH v4] refs: loosen restrictions on wildcard '*' refspecs

[Junio C Hamano]

Jacob Keller <jacob.e.keller@intel.com> writes:

> diff --git a/refs.c b/refs.c
> index ce8cd8d45001..a65f16fedaa0 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -20,11 +20,12 @@ struct ref_lock {
>   * 2: ., look for a preceding . to reject .. in refs
>   * 3: {, look for a preceding @ to reject @{ in refs
>   * 4: A bad character: ASCII control characters, "~", "^", ":" or SP
> + * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set

The fact that this patch does not have to change the description for
'4:' is an indication that the original description for '4:' was
incomplete.  Otherwise the original would have listed "*" among
others like "~", "^", and this patch would have updated it.

This mixes a fix/cleanup with an enhancement.

>   */
>  static unsigned char refname_disposition[256] = {
>  	1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
>  	4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
> -	4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1,
> +	4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
>  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
>  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
>  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
> @@ -71,11 +72,13 @@ static unsigned char refname_disposition[256] = {
>   * - any path component of it begins with ".", or
>   * - it has double dots "..", or
>   * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
> - * - it ends with a "/".
> - * - it ends with ".lock"
> - * - it contains a "\" (backslash)
> + * - it ends with a "/", or
> + * - it ends with ".lock", or
> + * - it contains a "\" (backslash), or
> + * - it contains a "@{" portion, or
> + * - it contains a '*' unless REFNAME_REFSPEC_PATTERN is set
>   */

This also mixes a fix/cleanup with an enhancement.  The original
should have had these ", or" but it didn't.

Can you split this patch into two, i.e.

 * [1/2] is to only clean-up the places these two hunks apply,
   without changing the behaviour at all.

   Please make sure that updated description for "4:" covers
   everything that is "a bad character".  We noticed the lack of '*'
   only because of your patch, but I do not know (and did not check)
   if that was the only thing that was missing.

 * [2/2] is what you really wanted to do with this patch,
   i.e. updating the entry for '*' in the disposition table and all
   changes outside the above two hunks.

Thanks.