Re: [PATCH v3 5/9] ref-filter: add option to match literal pattern

On Mon, Jul 20, 2015 at 8:24 AM, Eric Sunshine [off-list ref] wrote:

On Sat, Jul 18, 2015 at 3:12 PM, Karthik Nayak [off-list ref] wrote:

quoted

Since 'ref-filter' only has an option to match path names add an
option for plain fnmatch pattern-matching.

This is to support the pattern matching options which are used in `git
tag -l` and `git branch -l` where we can match patterns like `git tag
-l foo*` which would match all tags which has a "foo*" pattern.

Signed-off-by: Karthik Nayak <redacted>
---

diff --git a/ref-filter.c b/ref-filter.c
index 85c561e..7ff3ded 100644
--- a/ref-filter.c
+++ b/ref-filter.c

@@ -966,6 +980,15 @@ static int match_name_as_path(const char **pattern, const char *refname)
        return 0;
 }

+static int filter_pattern_match(struct ref_filter *filter, const char *refname)
+{
+       if (!*filter->name_patterns)
+               return 1;
+       if (filter->match_as_path)
+               return match_name_as_path(filter->name_patterns, refname);
+       return match_pattern(filter->name_patterns, refname);
+}
+
 /*
  * Given a ref (sha1, refname), check if the ref belongs to the array
  * of sha1s. If the given ref is a tag, check if the given tag points

@@ -1034,7 +1057,7 @@ static int ref_filter_handler(const char *refname, const struct object_id *oid,
                return 0;
        }

-       if (*filter->name_patterns && !match_name_as_path(filter->name_patterns, refname))
+       if (!filter_pattern_match(filter, refname))
                return 0;

I find it much more difficult to grok the new logic due to
'*filter->name_patterns' having moved into the called function and its
negation inside the function returning 1 which is then negated (again)
upon return here. This sort of twisty logic places a higher cognitive
load on the reader. Retaining the original logic makes the code far
simpler to understand:

    if (*filter->name_patterns &&
        !filter_pattern_match(filter, refname))
        return 0;

although it's a bit less nicely encapsulated, so I dunno...

I think a comment before filter_pattern_match() and perhaps also one
inside it might help. For example something like:

/* Return 1 if the refname matches one of the patterns, otherwise 0. */
static int filter_pattern_match(struct ref_filter *filter, const char *refname)
{
       if (!*filter->name_patterns)
               return 1; /* No pattern always matches */
       if (filter->match_as_path)
               return match_name_as_path(filter->name_patterns, refname);
       return match_pattern(filter->name_patterns, refname);
}