parseopt: prevent KEEP_UNKNOWN and STOP_AT_NON_OPTION from being used together

As suggested by Junio, disallow the flags PARSE_OPT_KEEP_UNKNOWN and
PARSE_OPT_STOP_AT_NON_OPTION to be turned on at the same time, as a
value of an unknown option could be mistakenly classified as a
non-option, stopping the parser early.  E.g.:

	git cmd --known --unknown value arg0 arg1

The parser should have stopped at "arg0", but it already stops at
"value".

This patch makes parse_options() die if the two flags are used in
combination.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt
index 20b44ff..e66ca9f 100644
--- a/Documentation/technical/api-parse-options.txt
+++ b/Documentation/technical/api-parse-options.txt
@@ -96,7 +96,8 @@ Flags are the bitwise-or of:
 	`PARSE_OPT_STOP_AT_NON_OPTION` is set, the second argument in
 	`--unknown value` will be mistakenly interpreted as a
 	non-option, not as a value belonging to the unknown option,
-	stopping the parser early.
+	the parser early.  That's why parse_options() errors out if
+	both options are set.
 
 `PARSE_OPT_NO_INTERNAL_HELP`::
 	By default, parse_options() handles `-h`, `--help` and