[PATCHv3] rev-parse --parseopt: allow [*=?!] in argument hints

[Ilya Bobyr <ilya.bobyr@gmail.com>]

A line in the input to "rev-parse --parseopt" describes an option by
listing a short and/or long name, optional flags [*=?!], argument hint,
and then whitespace and help string.

We did not allow any of the [*=?!] characters in the argument hints.
The following input

    pair=key=value  equals sign in the hint

used to generate a help line like this:

    --pair=key <value>   equals sign in the hint

and used to expect "pair=key" as the argument name.

That is not very helpful as we generally do not want any of the [*=?!]
characters in the argument names.  But we do want to use at least the
equals sign in the argument hints.

Update the parser to make long argument names stop at the first [*=?!]
character.

Add test case with equals sign in the argument hint and updated the test
to perform all the operations in test_expect_success matching the
t/README requirements and allowing commands like

    ./t1502-rev-parse-parseopt.sh --run=1-2

to stop at the test case 2 without any further modification of the test
state area.

Signed-off-by: Ilya Bobyr <ilya.bobyr@gmail.com>
---

On 7/13/2015 2:55 PM, Junio C Hamano wrote:
> ilya.bobyr@gmail.com writes:
>
>> Junio, thank you very much for all the comments.  I hope I have included
>> all of the suggestions you made.  Please, let me know if I have missed
>> anything or if there is something else you think should be improved.
>
> There were a few that still remained, which I locally amended.
> Please check what is queued on 'pu'.

Sorry about that %)
I have included add the changes from 'pu' into this patch as well as your
comments.

>> diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
>> index c483100..2ea169d 100644
>> --- a/Documentation/git-rev-parse.txt
>> +++ b/Documentation/git-rev-parse.txt
>> @@ -311,8 +311,8 @@ Each line of options has this format:
>>  `<opt-spec>`::
>>  	its format is the short option character, then the long option name
>>  	separated by a comma. Both parts are not required, though at least one
>> -	is necessary. `h,help`, `dry-run` and `f` are all three correct
>> -	`<opt-spec>`.
>> +	is necessary. May not contain any of the `<flags>` characters.
>> +	`h,help`, `dry-run` and `f` are all three correct `<opt-spec>`.
>
> "are examples of correct <opt-spec>"?

Fixed.

>>  
>>  `<flags>`::
>>  	`<flags>` are of `*`, `=`, `?` or `!`.
>> @@ -331,8 +331,9 @@ Each line of options has this format:
>>  `<arg-hint>`::
>>  	`<arg-hint>`, if specified, is used as a name of the argument in the
>>  	help output, for options that take arguments. `<arg-hint>` is
>> -	terminated by the first whitespace.  It is customary to use a
>> -	dash to separate words in a multi-word argument hint.
>> +	terminated by the first whitespace.  It may contain any of the
>> +	`<flags>` characters after the first character. It is customary to
>> +	use a dash to separate words in a multi-word argument hint.
>
> I think no change in this hunk is necessary for two reasons:
>
>  - You already said in <opt-spec> that any letters used for flags
>    cannot be used there, implying that the way rules are described
>    in the document around here is that anything is allowed unless
>    explicitly prohibited, which makes "It may contain..."
>    unnecessary.
>
>  - It may be worth saying "It may not contains any whitespace", but
>    that is already implied with the existing "is terminated by the
>    first whitespace".

I thought that if someone is reading only the <arg-hint> part it makes it
easier to understan what can they use.  If one reads description of all of
the pieces it is indeed redundant.

I have removed this hunk from the patch.

>> +		if (s - sb.buf == 1) /* short option only */
>> +			o->short_name = *sb.buf;
>> +		else if (sb.buf[1] != ',') /* long option only */
>> +			o->long_name = xmemdupz(sb.buf, s - sb.buf);
>> +		else {
>> +			o->short_name = *sb.buf;
>> +			o->long_name = xmemdupz(sb.buf + 2, s - sb.buf - 2);
>> +		}
>> +
>> +		/* type */
>
> s/type/flags/?

Fixed.

>> +		while (s < help) {
>> +			switch (*s++) {
>>  			case '=':
>>  				o->flags &= ~PARSE_OPT_NOARG;
>> -				break;
>> +				continue;
>>  			case '?':
>>  				o->flags &= ~PARSE_OPT_NOARG;
>>  				o->flags |= PARSE_OPT_OPTARG;
>> -				break;
>> +				continue;
>
> The updated code was a lot more pleasant read compared to the
> original (and the v1 patch).

Agreed :)


On 7/13/2015 4:19 AM, Philip Oakley wrote:
> From: <ilya.bobyr@gmail.com>
>> From: Ilya Bobyr <ilya.bobyr@gmail.com>
>>
>> [...]
>>
>> I have also made a slight addition to the man page to clarify the <flags>
>> parsing, based on the Philip Oakley comment.  Not sure if it is at the
>> level Philip wants it to be.  Please, let me know if you think it is still
>> not good enough. 
>
> The doc patch looks good. I've made one minor suggestion for clarity.
>
> I hadn't noticed the reverse order parsing that Junio pointed out. The
> new wording makes it clear that the flag chars can only occur in the
> arg-name-hint, and after the initial non-flag character. 

I thought that the fact that it used to parse in reverse is kind of a low
level implementation detail.  And an example that I have inserted instead
makes it easier to understand what the change is about.  After all, the
fact that it used to parse in reverse, I think, is of no real value after
the change is in place.


 Documentation/git-rev-parse.txt |  4 +-
 builtin/rev-parse.c             | 57 +++++++++++++-----------
 t/t1502-rev-parse-parseopt.sh   | 99 +++++++++++++++++++++++++----------------
 3 files changed, 92 insertions(+), 68 deletions(-)

diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index c483100..b6c6326 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -311,8 +311,8 @@ Each line of options has this format:
 `<opt-spec>`::
 	its format is the short option character, then the long option name
 	separated by a comma. Both parts are not required, though at least one
-	is necessary. `h,help`, `dry-run` and `f` are all three correct
-	`<opt-spec>`.
+	is necessary. May not contain any of the `<flags>` characters.
+	`h,help`, `dry-run` and `f` are examples of correct `<opt-spec>`.
 
 `<flags>`::
 	`<flags>` are of `*`, `=`, `?` or `!`.
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index b623239..02d747d 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -371,6 +371,7 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 					N_("output in stuck long form")),
 		OPT_END(),
 	};
+	static const char * const flag_chars = "*=?!";
 
 	struct strbuf sb = STRBUF_INIT, parsed = STRBUF_INIT;
 	const char **usage = NULL;
@@ -400,7 +401,7 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 	/* parse: (<short>|<short>,<long>|<long>)[*=?!]*<arghint>? SP+ <help> */
 	while (strbuf_getline(&sb, stdin, '\n') != EOF) {
 		const char *s;
-		const char *end;
+		const char *help;
 		struct option *o;
 
 		if (!sb.len)
@@ -410,54 +411,56 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 		memset(opts + onb, 0, sizeof(opts[onb]));
 
 		o = &opts[onb++];
-		s = strchr(sb.buf, ' ');
-		if (!s || *sb.buf == ' ') {
+		help = strchr(sb.buf, ' ');
+		if (!help || *sb.buf == ' ') {
 			o->type = OPTION_GROUP;
 			o->help = xstrdup(skipspaces(sb.buf));
 			continue;
 		}
 
 		o->type = OPTION_CALLBACK;
-		o->help = xstrdup(skipspaces(s));
+		o->help = xstrdup(skipspaces(help));
 		o->value = &parsed;
 		o->flags = PARSE_OPT_NOARG;
 		o->callback = &parseopt_dump;
 
-		/* Possible argument name hint */
-		end = s;
-		while (s > sb.buf && strchr("*=?!", s[-1]) == NULL)
-			--s;
-		if (s != sb.buf && s != end)
-			o->argh = xmemdupz(s, end - s);
-		if (s == sb.buf)
-			s = end;
-
-		while (s > sb.buf && strchr("*=?!", s[-1])) {
-			switch (*--s) {
+		/* name(s) */
+		s = strpbrk(sb.buf, flag_chars);
+		if (s == NULL)
+			s = help;
+
+		if (s - sb.buf == 1) /* short option only */
+			o->short_name = *sb.buf;
+		else if (sb.buf[1] != ',') /* long option only */
+			o->long_name = xmemdupz(sb.buf, s - sb.buf);
+		else {
+			o->short_name = *sb.buf;
+			o->long_name = xmemdupz(sb.buf + 2, s - sb.buf - 2);
+		}
+
+		/* flags */
+		while (s < help) {
+			switch (*s++) {
 			case '=':
 				o->flags &= ~PARSE_OPT_NOARG;
-				break;
+				continue;
 			case '?':
 				o->flags &= ~PARSE_OPT_NOARG;
 				o->flags |= PARSE_OPT_OPTARG;
-				break;
+				continue;
 			case '!':
 				o->flags |= PARSE_OPT_NONEG;
-				break;
+				continue;
 			case '*':
 				o->flags |= PARSE_OPT_HIDDEN;
-				break;
+				continue;
 			}
+			s--;
+			break;
 		}
 
-		if (s - sb.buf == 1) /* short option only */
-			o->short_name = *sb.buf;
-		else if (sb.buf[1] != ',') /* long option only */
-			o->long_name = xmemdupz(sb.buf, s - sb.buf);
-		else {
-			o->short_name = *sb.buf;
-			o->long_name = xmemdupz(sb.buf + 2, s - sb.buf - 2);
-		}
+		if (s < help)
+			o->argh = xmemdupz(s, help - s);
 	}
 	strbuf_release(&sb);
 
diff --git a/t/t1502-rev-parse-parseopt.sh b/t/t1502-rev-parse-parseopt.sh
index ebe7c3b..63392a8 100755
--- a/t/t1502-rev-parse-parseopt.sh
+++ b/t/t1502-rev-parse-parseopt.sh
@@ -3,7 +3,40 @@
 test_description='test git rev-parse --parseopt'
 . ./test-lib.sh
 
-sed -e 's/^|//' >expect <<\END_EXPECT
+test_expect_success 'setup optionspec' '
+	sed -e "s/^|//" >optionspec <<\EOF
+|some-command [options] <args>...
+|
+|some-command does foo and bar!
+|--
+|h,help    show the help
+|
+|foo       some nifty option --foo
+|bar=      some cool option --bar with an argument
+|b,baz     a short and long option
+|
+| An option group Header
+|C?        option C with an optional argument
+|d,data?   short and long option with an optional argument
+|
+| Argument hints
+|B=arg     short option required argument
+|bar2=arg  long option required argument
+|e,fuz=with-space  short and long option required argument
+|s?some    short option optional argument
+|long?data long option optional argument
+|g,fluf?path     short and long option optional argument
+|longest=very-long-argument-hint  a very long argument hint
+|pair=key=value  with an equals sign in the hint
+|short-hint=a    with a one simbol hint
+|
+|Extras
+|extra1    line above used to cause a segfault but no longer does
+EOF
+'
+
+test_expect_success 'test --parseopt help output' '
+	sed -e "s/^|//" >expect <<\END_EXPECT &&
 |cat <<\EOF
 |usage: some-command [options] <args>...
 |
@@ -28,49 +61,23 @@ sed -e 's/^|//' >expect <<\END_EXPECT
 |    -g, --fluf[=<path>]   short and long option optional argument
 |    --longest <very-long-argument-hint>
 |                          a very long argument hint
+|    --pair <key=value>    with an equals sign in the hint
+|    --short-hint <a>      with a one simbol hint
 |
 |Extras
 |    --extra1              line above used to cause a segfault but no longer does
 |
 |EOF
 END_EXPECT
-
-sed -e 's/^|//' >optionspec <<\EOF
-|some-command [options] <args>...
-|
-|some-command does foo and bar!
-|--
-|h,help    show the help
-|
-|foo       some nifty option --foo
-|bar=      some cool option --bar with an argument
-|b,baz     a short and long option
-|
-| An option group Header
-|C?        option C with an optional argument
-|d,data?   short and long option with an optional argument
-|
-| Argument hints
-|B=arg     short option required argument
-|bar2=arg  long option required argument
-|e,fuz=with-space  short and long option required argument
-|s?some    short option optional argument
-|long?data long option optional argument
-|g,fluf?path     short and long option optional argument
-|longest=very-long-argument-hint  a very long argument hint
-|
-|Extras
-|extra1    line above used to cause a segfault but no longer does
-EOF
-
-test_expect_success 'test --parseopt help output' '
 	test_expect_code 129 git rev-parse --parseopt -- -h > output < optionspec &&
 	test_i18ncmp expect output
 '
 
-cat > expect <<EOF
+test_expect_success 'setup expect.1' "
+	cat > expect <<EOF
 set -- --foo --bar 'ham' -b -- 'arg'
 EOF
+"
 
 test_expect_success 'test --parseopt' '
 	git rev-parse --parseopt -- --foo --bar=ham --baz arg < optionspec > output &&
@@ -82,9 +89,11 @@ test_expect_success 'test --parseopt with mixed options and arguments' '
 	test_cmp expect output
 '
 
-cat > expect <<EOF
+test_expect_success 'setup expect.2' "
+	cat > expect <<EOF
 set -- --foo -- 'arg' '--bar=ham'
 EOF
+"
 
 test_expect_success 'test --parseopt with --' '
 	git rev-parse --parseopt -- --foo -- arg --bar=ham < optionspec > output &&
@@ -96,54 +105,66 @@ test_expect_success 'test --parseopt --stop-at-non-option' '
 	test_cmp expect output
 '
 
-cat > expect <<EOF
+test_expect_success 'setup expect.3' "
+	cat > expect <<EOF
 set -- --foo -- '--' 'arg' '--bar=ham'
 EOF
+"
 
 test_expect_success 'test --parseopt --keep-dashdash' '
 	git rev-parse --parseopt --keep-dashdash -- --foo -- arg --bar=ham < optionspec > output &&
 	test_cmp expect output
 '
 
-cat >expect <<EOF
+test_expect_success 'setup expect.4' "
+	cat >expect <<EOF
 set -- --foo -- '--' 'arg' '--spam=ham'
 EOF
+"
 
 test_expect_success 'test --parseopt --keep-dashdash --stop-at-non-option with --' '
 	git rev-parse --parseopt --keep-dashdash --stop-at-non-option -- --foo -- arg --spam=ham <optionspec >output &&
 	test_cmp expect output
 '
 
-cat > expect <<EOF
+test_expect_success 'setup expect.5' "
+	cat > expect <<EOF
 set -- --foo -- 'arg' '--spam=ham'
 EOF
+"
 
 test_expect_success 'test --parseopt --keep-dashdash --stop-at-non-option without --' '
 	git rev-parse --parseopt --keep-dashdash --stop-at-non-option -- --foo arg --spam=ham <optionspec >output &&
 	test_cmp expect output
 '
 
-cat > expect <<EOF
+test_expect_success 'setup expect.6' "
+	cat > expect <<EOF
 set -- --foo --bar='z' --baz -C'Z' --data='A' -- 'arg'
 EOF
+"
 
 test_expect_success 'test --parseopt --stuck-long' '
 	git rev-parse --parseopt --stuck-long -- --foo --bar=z -b arg -CZ -dA <optionspec >output &&
 	test_cmp expect output
 '
 
-cat > expect <<EOF
+test_expect_success 'setup expect.7' "
+	cat > expect <<EOF
 set -- --data='' -C --baz -- 'arg'
 EOF
+"
 
 test_expect_success 'test --parseopt --stuck-long and empty optional argument' '
 	git rev-parse --parseopt --stuck-long -- --data= arg -C -b <optionspec >output &&
 	test_cmp expect output
 '
 
-cat > expect <<EOF
+test_expect_success 'setup expect.8' "
+	cat > expect <<EOF
 set -- --data --baz -- 'arg'
 EOF
+"
 
 test_expect_success 'test --parseopt --stuck-long and long option with unset optional argument' '
 	git rev-parse --parseopt --stuck-long -- --data arg -b <optionspec >output &&
-- 
2.4.5