diff: differentiate error handling in parse_color_moved_ws
diff mbox series

Message ID 20181102212316.208433-1-sbeller@google.com
State New
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Series
  • diff: differentiate error handling in parse_color_moved_ws
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Commit Message

Stefan Beller Nov. 2, 2018, 9:23 p.m. UTC
As we check command line options more strictly and allow configuration
variables to be parsed more leniently, we need take different actions
based on whether an unknown value is given on the command line or in the
config.

Move the die() call out of parse_color_moved_ws into the parsing
of command line options. As the function returns a bit field, change
its signature to return an unsigned instead of an int; add a new bit
to signal errors. Once the error is signaled, we discard the other
bits, such that it doesn't matter if the error bit overlaps with any
other bit.

Signed-off-by: Stefan Beller <sbeller@google.com>
---

This is a fresh attempt to cleanup the sloppy part that was mentioned
in https://public-inbox.org/git/xmqqa7nkf6o4.fsf@gitster-ct.c.googlers.com/

Another thing to follow up is to have color-moved-ws imply color-moved.

Thanks,
Stefan


 diff.c | 21 ++++++++++++++-------
 diff.h |  3 ++-
 2 files changed, 16 insertions(+), 8 deletions(-)

Comments

Junio C Hamano Nov. 3, 2018, 1:21 a.m. UTC | #1
Stefan Beller <sbeller@google.com> writes:

>  
> -static int parse_color_moved_ws(const char *arg)
> +static unsigned parse_color_moved_ws(const char *arg)
>  {
>  	int ret = 0;
>  	struct string_list l = STRING_LIST_INIT_DUP;
> @@ -312,15 +312,19 @@ static int parse_color_moved_ws(const char *arg)
>  			ret |= XDF_IGNORE_WHITESPACE;
>  		else if (!strcmp(sb.buf, "allow-indentation-change"))
>  			ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
> -		else
> +		else {
> +			ret |= COLOR_MOVED_WS_ERROR;
>  			error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
> +		}
> ...  
>  	} else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
> -		options->color_moved_ws_handling = parse_color_moved_ws(arg);
> +		unsigned cm = parse_color_moved_ws(arg);
> +		if (cm & COLOR_MOVED_WS_ERROR)
> +			die("bad --color-moved-ws argument: %s", arg);
> +		options->color_moved_ws_handling = cm;

Excellent.

Will queue.  Perhaps a test or two can follow to ensure a bad value
from config does not kill while a command line does?

Thanks.
Junio C Hamano Nov. 5, 2018, 6:12 a.m. UTC | #2
Junio C Hamano <gitster@pobox.com> writes:

> Stefan Beller <sbeller@google.com> writes:
>
>>  
>> -static int parse_color_moved_ws(const char *arg)
>> +static unsigned parse_color_moved_ws(const char *arg)
>>  {
>>  	int ret = 0;
>>  	struct string_list l = STRING_LIST_INIT_DUP;
>> @@ -312,15 +312,19 @@ static int parse_color_moved_ws(const char *arg)
>>  			ret |= XDF_IGNORE_WHITESPACE;
>>  		else if (!strcmp(sb.buf, "allow-indentation-change"))
>>  			ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
>> -		else
>> +		else {
>> +			ret |= COLOR_MOVED_WS_ERROR;
>>  			error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
>> +		}
>> ...  
>>  	} else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
>> -		options->color_moved_ws_handling = parse_color_moved_ws(arg);
>> +		unsigned cm = parse_color_moved_ws(arg);
>> +		if (cm & COLOR_MOVED_WS_ERROR)
>> +			die("bad --color-moved-ws argument: %s", arg);
>> +		options->color_moved_ws_handling = cm;
>
> Excellent.
>
> Will queue.  Perhaps a test or two can follow to ensure a bad value
> from config does not kill while a command line does?

Wait.  This does not fix

	git -c diff.colormovedws=nonsense diff

that dies with an error message---it should ignore the config and at
moat issue a warning.

The command line handling of

	git diff --color-moved-ws=nonsense

does correctly die, but it first says "error: ignoring" before
saying "fatal: bad argument", which is suboptimal.

So, not so excellent (yet) X-<.
Stefan Beller Nov. 5, 2018, 6:19 p.m. UTC | #3
On Sun, Nov 4, 2018 at 10:12 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> Junio C Hamano <gitster@pobox.com> writes:
>
> > Stefan Beller <sbeller@google.com> writes:
> >
> >>
> >> -static int parse_color_moved_ws(const char *arg)
> >> +static unsigned parse_color_moved_ws(const char *arg)
> >>  {
> >>      int ret = 0;
> >>      struct string_list l = STRING_LIST_INIT_DUP;
> >> @@ -312,15 +312,19 @@ static int parse_color_moved_ws(const char *arg)
> >>                      ret |= XDF_IGNORE_WHITESPACE;
> >>              else if (!strcmp(sb.buf, "allow-indentation-change"))
> >>                      ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
> >> -            else
> >> +            else {
> >> +                    ret |= COLOR_MOVED_WS_ERROR;
> >>                      error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
> >> +            }
> >> ...
> >>      } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
> >> -            options->color_moved_ws_handling = parse_color_moved_ws(arg);
> >> +            unsigned cm = parse_color_moved_ws(arg);
> >> +            if (cm & COLOR_MOVED_WS_ERROR)
> >> +                    die("bad --color-moved-ws argument: %s", arg);
> >> +            options->color_moved_ws_handling = cm;
> >
> > Excellent.
> >
> > Will queue.  Perhaps a test or two can follow to ensure a bad value
> > from config does not kill while a command line does?
>
> Wait.  This does not fix
>
>         git -c diff.colormovedws=nonsense diff
>
> that dies with an error message---it should ignore the config and at
> moat issue a warning.

$ git -c core.abbrev=41 diff
error: abbrev length out of range: 41
fatal: unable to parse 'core.abbrev' from command-line config
$ ./git -c  diff.colormovedws=nonsense diff HEAD
error: ignoring unknown color-moved-ws mode 'nonsense'
fatal: unable to parse 'diff.colormovedws' from command-line config

Ah, I see the issue there. We actually have to return 'success' to the
config machinery after the warning claiming ignoring the setting or
we'd have to reword the warning to state we're not ignoring the bogus
setting.

> The command line handling of
>
>         git diff --color-moved-ws=nonsense
>
> does correctly die, but it first says "error: ignoring" before
> saying "fatal: bad argument", which is suboptimal.

So to find the analogous here, maybe:

$ git diff --color=bogus
error: option `color' expects "always", "auto", or "never"

> So, not so excellent (yet) X-<.

So to reach excellence, we'd want to reword the warning
message and a test.

Thanks,
Stefan

Patch
diff mbox series

diff --git a/diff.c b/diff.c
index 8647db3d30..f21f8b0332 100644
--- a/diff.c
+++ b/diff.c
@@ -291,7 +291,7 @@  static int parse_color_moved(const char *arg)
 		return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 }
 
-static int parse_color_moved_ws(const char *arg)
+static unsigned parse_color_moved_ws(const char *arg)
 {
 	int ret = 0;
 	struct string_list l = STRING_LIST_INIT_DUP;
@@ -312,15 +312,19 @@  static int parse_color_moved_ws(const char *arg)
 			ret |= XDF_IGNORE_WHITESPACE;
 		else if (!strcmp(sb.buf, "allow-indentation-change"))
 			ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
-		else
+		else {
+			ret |= COLOR_MOVED_WS_ERROR;
 			error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
+		}
 
 		strbuf_release(&sb);
 	}
 
 	if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
-	    (ret & XDF_WHITESPACE_FLAGS))
-		die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
+	    (ret & XDF_WHITESPACE_FLAGS)) {
+		error(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
+		ret |= COLOR_MOVED_WS_ERROR;
+	}
 
 	string_list_clear(&l, 0);
 
@@ -341,8 +345,8 @@  int git_diff_ui_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 	if (!strcmp(var, "diff.colormovedws")) {
-		int cm = parse_color_moved_ws(value);
-		if (cm < 0)
+		unsigned cm = parse_color_moved_ws(value);
+		if (cm & COLOR_MOVED_WS_ERROR)
 			return -1;
 		diff_color_moved_ws_default = cm;
 		return 0;
@@ -5035,7 +5039,10 @@  int diff_opt_parse(struct diff_options *options,
 			die("bad --color-moved argument: %s", arg);
 		options->color_moved = cm;
 	} else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
-		options->color_moved_ws_handling = parse_color_moved_ws(arg);
+		unsigned cm = parse_color_moved_ws(arg);
+		if (cm & COLOR_MOVED_WS_ERROR)
+			die("bad --color-moved-ws argument: %s", arg);
+		options->color_moved_ws_handling = cm;
 	} else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
 		options->use_color = 1;
 		options->word_diff = DIFF_WORDS_COLOR;
diff --git a/diff.h b/diff.h
index ce5e8a8183..9e8061ca29 100644
--- a/diff.h
+++ b/diff.h
@@ -225,7 +225,8 @@  struct diff_options {
 
 	/* XDF_WHITESPACE_FLAGS regarding block detection are set at 2, 3, 4 */
 	#define COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE (1<<5)
-	int color_moved_ws_handling;
+	#define COLOR_MOVED_WS_ERROR (1<<0)
+	unsigned color_moved_ws_handling;
 
 	struct repository *repo;
 };