list-objects-filter-options: allow mult. --filter

Allow combining of multiple filters by simply repeating the --filter
flag. Before this patch, the user had to combine them in a single flag
somewhat awkwardly (e.g. --filter=combine:FOO+BAR), including
URL-encoding the individual filters.

To make this work, in the --filter flag parsing callback, rather than
error out when we detect that the filter_options struct is already
populated, we modify it in-place to contain the added sub-filter. The
existing sub-filter becomes the lhs of the combined filter, and the
next sub-filter becomes the rhs. We also have to URL-encode the LHS and
RHS sub-filters.

We can simplify the operation if the LHS is already a combine: filter.
In that case, we just append the URL-encoded RHS sub-filter to the LHS
spec to get the new spec.

Helped-by: Emily Shaffer <emilyshaffer@google.com>
Helped-by: Jeff Hostetler <git@jeffhostetler.com>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/list-objects-filter-options.h b/list-objects-filter-options.h
index bb33303..d8bc7e9 100644
--- a/list-objects-filter-options.h
+++ b/list-objects-filter-options.h
@@ -63,6 +63,17 @@ struct list_objects_filter_options {
 /* Normalized command line arguments */
 #define CL_ARG__FILTER "filter"
 
+void list_objects_filter_die_if_populated(
+	struct list_objects_filter_options *filter_options);
+
+/*
+ * Parses the filter spec string given by arg and either (1) simply places the
+ * result in filter_options if it is not yet populated or (2) combines it with
+ * the filter already in filter_options if it is already populated. In the case
+ * of (2), the filter specs are combined as if specified with 'combine:'.
+ *
+ * Dies and prints a user-facing message if an error occurs.
+ */
 int parse_list_objects_filter(
 	struct list_objects_filter_options *filter_options,
 	const char *arg);