Re: [PATCH 4/4] parse-options: clarify PARSE_OPT_NONEG does not reject negative numbers

"Michael Montalbo via GitGitGadget" [off-list ref] writes:

From: Michael Montalbo <redacted>

The name "NONEG" can be misread as "no negative [values]" when it
actually means "no [boolean] negation" (the --no-* form).

When --inter-hunk-context and -U/--unified were converted from a
custom parser to OPT_INTEGER_F with PARSE_OPT_NONEG in d473e2e0e8
and 16ed6c97cc, the implicit rejection of negative values (via
isdigit() in the old opt_arg() parser) was silently lost. The
previous commits in this series fix the resulting bugs.

I do not think _NONEG has anything to do with the bug.  It was
purely to reject --no-unified and --no-inter-hunk-context.

And there was no change to remove PARSE_OPT_NONEG from anywhere and
use OPT_UNSIGNED instead to fix any of the bugs fixed in this
series, ...

... I do not think the two additional sentences are warranted.  Stop
at clarifying what negated _means_ (i.e., rejects "--no-<option>"),
without adding what negated does _not_ mean.

  *   PARSE_OPT_HIDDEN: this option is skipped in the default usage, and
  *                     shown only in the full usage.
  *   PARSE_OPT_LASTARG_DEFAULT: says that this option will take the default

On Sat, May 9, 2026 at 3:01 PM Junio C Hamano [off-list ref] wrote:

"Michael Montalbo via GitGitGadget" [off-list ref] writes:

quoted

From: Michael Montalbo <redacted>

The name "NONEG" can be misread as "no negative [values]" when it
actually means "no [boolean] negation" (the --no-* form).

When --inter-hunk-context and -U/--unified were converted from a
custom parser to OPT_INTEGER_F with PARSE_OPT_NONEG in d473e2e0e8
and 16ed6c97cc, the implicit rejection of negative values (via
isdigit() in the old opt_arg() parser) was silently lost. The
previous commits in this series fix the resulting bugs.

I do not think _NONEG has anything to do with the bug.  It was
purely to reject --no-unified and --no-inter-hunk-context.

You are right this was a mistaken assumption on my part.

And there was no change to remove PARSE_OPT_NONEG from anywhere and
use OPT_UNSIGNED instead to fix any of the bugs fixed in this
series, ...

Right, PARSE_OPT_NONEG is still enabled implicitly by OPT_UNSIGNED so
PARSE_OPT_NONEG really has no part in the story.

quoted

Add a clarifying note to the flag documentation.

Signed-off-by: Michael Montalbo <redacted>
---
 parse-options.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/parse-options.h b/parse-options.h
index 706de9729f..c0a3a3dcae 100644
--- a/parse-options.h
+++ b/parse-options.h

@@ -116,7 +116,10 @@ typedef int parse_opt_subcommand_fn(int argc, const char **argv,
  *   mask of parse_opt_option_flags.
  *   PARSE_OPT_OPTARG: says that the argument is optional (not for BOOLEANs)
  *   PARSE_OPT_NOARG: says that this option does not take an argument
- *   PARSE_OPT_NONEG: says that this option cannot be negated
+ *   PARSE_OPT_NONEG: says that this option cannot be negated (i.e.
+ *                   prevents --no-<option> boolean form). Does not reject
+ *                   negative numeric values like --option=-1. Use
+ *                   OPT_UNSIGNED for options that must be non-negative.

... I do not think the two additional sentences are warranted.  Stop
at clarifying what negated _means_ (i.e., rejects "--no-<option>"),
without adding what negated does _not_ mean.

Ok, will remove the latter portion of the change in a follow-up.

quoted

  *   PARSE_OPT_HIDDEN: this option is skipped in the default usage, and
  *                     shown only in the full usage.
  *   PARSE_OPT_LASTARG_DEFAULT: says that this option will take the default