parse-options: simplify positivation handling

We accept the positive version of options whose long name starts with
"no-" and are defined without the flag PARSE_OPT_NONEG.  E.g. git clone
has an explicitly defined --no-checkout option and also implicitly
accepts --checkout to override it.

parse_long_opt() handles that by restarting the option matching with the
positive version when it finds that only the current option definition
starts with "no-", but not the user-supplied argument.  This code is
located almost at the end of the matching logic.

Avoid the need for a restart by moving the code up.  We don't have to
check the positive arg against the negative long_name at all -- the
"no-" prefix of the latter makes a match impossible.  Skip it and toggle
OPT_UNSET right away to simplify the control flow.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/parse-options.c b/parse-options.c
index 0dd07eec82b2750af972e380982aeeeead920175..e4fda09af49a5db6406dc35bd0fcfe6f2176737e 100644 (file)
--- a/parse-options.c
+++ b/parse-options.c
@@ -369,7 +369,11 @@ static enum parse_opt_result parse_long_opt(
                if (!long_name)
                        continue;
 
-again:
+               if (!starts_with(arg, "no-") &&
+                   !(options->flags & PARSE_OPT_NONEG) &&
+                   skip_prefix(long_name, "no-", &long_name))
+                       opt_flags |= OPT_UNSET;
+
                if (!skip_prefix(arg, long_name, &rest))
                        rest = NULL;
                if (!rest) {
@@ -403,13 +407,8 @@ is_abbreviated:
                                goto is_abbreviated;
                        }
                        /* negated? */
-                       if (!starts_with(arg, "no-")) {
-                               if (skip_prefix(long_name, "no-", &long_name)) {
-                                       opt_flags |= OPT_UNSET;
-                                       goto again;
-                               }
+                       if (!starts_with(arg, "no-"))
                                continue;
-                       }
                        flags |= OPT_UNSET;
                        if (!skip_prefix(arg + 3, long_name, &rest)) {
                                /* abbreviated and negated? */