rev-list: support --no-filter argument

Teach rev-list to support --no-filter to override a
previous --filter=<filter_spec> argument.  This is
to be consistent with commands that use OPT_PARSE
macros.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/rev-list-options.txt

@@ -715,16 +715,21 @@ ifdef::git-rev-list[]
 The form '--filter=blob:none' omits all blobs.
 +
 The form '--filter=blob:limit=<n>[kmg]' omits blobs larger than n bytes
-or units.  The value may be zero.
+or units.  n may be zero.  The suffixes k, m, and g can be used to name
+units in KiB, MiB, or GiB.  For example, 'blob:limit=1k' is the same
+as 'blob:limit=1024'.
 +
-The form '--filter=sparse:oid=<oid-ish>' uses a sparse-checkout
-specification contained in the object (or the object that the expression
-evaluates to) to omit blobs that would not be not required for a
-sparse checkout on the requested refs.
+The form '--filter=sparse:oid=<blob-ish>' uses a sparse-checkout
+specification contained in the blob (or blob-expression) '<blob-ish>'
+to omit blobs that would not be not required for a sparse checkout on
+the requested refs.
 +
 The form '--filter=sparse:path=<path>' similarly uses a sparse-checkout
 specification contained in <path>.
 
+--no-filter::
+	Turn off any previous `--filter=` argument.
+
 --filter-print-omitted::
 	Only useful with `--filter=`; prints a list of the objects omitted
 	by the filter.	Object IDs are prefixed with a ``~'' character.

builtin/rev-list.c

@@ -403,6 +403,10 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 				    filter_options.filter_spec);
 			continue;
 		}
+		if (!strcmp(arg, ("--no-" CL_ARG__FILTER))) {
+			list_objects_filter_release(&filter_options);
+			continue;
+		}
 		if (!strcmp(arg, "--filter-print-omitted")) {
 			arg_print_omitted = 1;
 			continue;