argp: argp.doc prints incorrectly when it starts with "\v" [BZ #19038]

  Hello,
Reposting this patch for BZ #19038, as now I have the copyright assignment
with FSF.

Here the bug is that; if doc string starts with `\v` then the whole doc string
is printed both before and after the options.

The bug can be reproduced using following code.

#include<stdlib.h>
#include<argp.h>

static char doc[] = "\vthis is post_doc";
static struct argp argp = {NULL, NULL, NULL, doc};

int main(int argc, char *args[]){
     argp_parse(&argp, argc, args, 0, 0, NULL);
}

Currently we get the output of this code as

$ argp-help --help
Usage: argp-help [OPTION...]

this is post_doc

  -?, --help                 Give this help list
      --usage                Give a short usage message

this is post_doc

As mentioned in the comment on bugzilla, the first occurrence of
"this is post_doc" is erroneous.

This is happening because in argp-help.c in the function argp_doc 'char *vt'
(which is responsible for determining the position for vertical tab in the
doc string) is being initialized only once,

It should be initialized for each child in the documentation.

The next thing is the complete doc string needs to be printed only if
1. If there is only one child in the doc string
   and the doc string does not start with '\v'.
2. The argument 'first_only' to the function 'argp_doc' is 0.

After applying the patch we get the output as following.

$ argp-help --help
Usage: argp-help [OPTION...]

  -?, --help                 Give this help list
      --usage                Give a short usage message

this is post_doc

A test case for this is also added in the patch.
Following is the patch for this bug.

From 36cfdeab88ec3ecfe971cd70c798a9615d6adc41 Mon Sep 17 00:00:00 2001
From: Girish Joshi <girish946@gmail.com>
Date: Thu, 6 Feb 2020 01:03:18 +0530
Subject: [PATCH] Fix argp.doc prints incorrectly when it starts with '\v' (Bug
 19038)

"char *vt" in the function "argp_doc" is initialized for every child in the doc.

The complete doc string is printed only in two cases.
1. There is only one child in the doc and the doc does not starts with '\v'.
2. Argument "first_only" to the function "argp_doc" is 0.

Added test argp/tst-argp3.c for this case.
---
 argp/Makefile    |  2 +-
 argp/argp-help.c | 10 +++++--
 argp/tst-argp3.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 77 insertions(+), 3 deletions(-)
 create mode 100644 argp/tst-argp3.c

+
--
2.21.1
  

Hello,
Can someone please review this patch?
Thanks.

Girish Joshi

On Tue, Mar 3, 2020 at 11:43 PM Girish Joshi <girish946@gmail.com> wrote:
>
> Hello,
> Reposting this patch for BZ #19038, as now I have the copyright assignment
> with FSF.
>
> Here the bug is that; if doc string starts with `\v` then the whole doc string
> is printed both before and after the options.
>
> The bug can be reproduced using following code.
>
> #include<stdlib.h>
> #include<argp.h>
>
> static char doc[] = "\vthis is post_doc";
> static struct argp argp = {NULL, NULL, NULL, doc};
>
> int main(int argc, char *args[]){
>      argp_parse(&argp, argc, args, 0, 0, NULL);
> }
>
> Currently we get the output of this code as
>
> $ argp-help --help
> Usage: argp-help [OPTION...]
>
> this is post_doc
>
>   -?, --help                 Give this help list
>       --usage                Give a short usage message
>
> this is post_doc
>
> As mentioned in the comment on bugzilla, the first occurrence of
> "this is post_doc" is erroneous.
>
> This is happening because in argp-help.c in the function argp_doc 'char *vt'
> (which is responsible for determining the position for vertical tab in the
> doc string) is being initialized only once,
>
> It should be initialized for each child in the documentation.
>
> The next thing is the complete doc string needs to be printed only if
> 1. If there is only one child in the doc string
>    and the doc string does not start with '\v'.
> 2. The argument 'first_only' to the function 'argp_doc' is 0.
>
> After applying the patch we get the output as following.
>
> $ argp-help --help
> Usage: argp-help [OPTION...]
>
>   -?, --help                 Give this help list
>       --usage                Give a short usage message
>
> this is post_doc
>
> A test case for this is also added in the patch.
> Following is the patch for this bug.
>
> From 36cfdeab88ec3ecfe971cd70c798a9615d6adc41 Mon Sep 17 00:00:00 2001
> From: Girish Joshi <girish946@gmail.com>
> Date: Thu, 6 Feb 2020 01:03:18 +0530
> Subject: [PATCH] Fix argp.doc prints incorrectly when it starts with '\v' (Bug
>  19038)
>
> "char *vt" in the function "argp_doc" is initialized for every child in the doc.
>
> The complete doc string is printed only in two cases.
> 1. There is only one child in the doc and the doc does not starts with '\v'.
> 2. Argument "first_only" to the function "argp_doc" is 0.
>
> Added test argp/tst-argp3.c for this case.
> ---
>  argp/Makefile    |  2 +-
>  argp/argp-help.c | 10 +++++--
>  argp/tst-argp3.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 77 insertions(+), 3 deletions(-)
>  create mode 100644 argp/tst-argp3.c
>
> diff --git a/argp/Makefile b/argp/Makefile
> index 1f9b074bed..0c0270ffef 100644
> --- a/argp/Makefile
> +++ b/argp/Makefile
> @@ -27,7 +27,7 @@ routines    = $(addprefix argp-, ba fmtstream
> fs-xinl help parse pv \
>                       pvh xinl eexst)
>
>  tests        = argp-test tst-argp1 bug-argp1 tst-argp2 bug-argp2 \
> -          tst-ldbl-argp
> +          tst-ldbl-argp tst-argp3
>
>  CFLAGS-argp-help.c += $(uses-callbacks) -fexceptions
>  CFLAGS-argp-parse.c += $(uses-callbacks)
> diff --git a/argp/argp-help.c b/argp/argp-help.c
> index 2bcd6549fd..8d213e4586 100644
>
> --- a/argp/argp-help.c
> +++ b/argp/argp-help.c
> @@ -1465,10 +1465,11 @@ argp_doc (const struct argp *argp, const
> struct argp_state *state,
>    size_t inp_text_limit = 0;
>    const char *doc = dgettext (argp->argp_domain, argp->doc);
>    const struct argp_child *child = argp->children;
> +  char *vt = 0;
>
>    if (doc)
>      {
> -      char *vt = strchr (doc, '\v');
> +      vt = strchr (doc, '\v');
>        inp_text = post ? (vt ? vt + 1 : 0) : doc;
>        inp_text_limit = (!post && vt) ? (vt - doc) : 0;
>      }
> @@ -1499,7 +1500,12 @@ argp_doc (const struct argp *argp, const struct
> argp_state *state,
>        if (text == inp_text && inp_text_limit)
>      __argp_fmtstream_write (stream, inp_text, inp_text_limit);
>        else
> -    __argp_fmtstream_puts (stream, text);
> +      {
> +        if ((!vt && !child) || (text == inp_text && !first_only))
> +        {
> +          __argp_fmtstream_puts (stream, text);
> +        }
> +      }
>
>        if (__argp_fmtstream_point (stream) > __argp_fmtstream_lmargin (stream))
>      __argp_fmtstream_putc (stream, '\n');
> diff --git a/argp/tst-argp3.c b/argp/tst-argp3.c
> new file mode 100644
> index 0000000000..cfdace2574
> --- /dev/null
> +++ b/argp/tst-argp3.c
> @@ -0,0 +1,68 @@
> +/* Test for argparse with leading '\v' in the doc string.
> +  Copyright (C) 2020 Free Software Foundation, Inc.
>
> +
> +  This program is free software: you can redistribute it and/or modify
> +  it under the terms of the GNU General Public License as published by
> +  the Free Software Foundation; either version 3 of the License, or
> +  (at your option) any later version.
> +
> +  This program is distributed in the hope that it will be useful,
> +  but WITHOUT ANY WARRANTY; without even the implied warranty of
> +  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +  GNU General Public License for more details.
> +
> +  You should have received a copy of the GNU General Public License
> +  along with this program.  If not, see <https://www.gnu.org/licenses/>.*/
> +
> +
> +#include<stdlib.h>
> +#include<argp.h>
> +
> +#include <support/capture_subprocess.h>
> +#include <support/check.h>
> +
> +
> +static char expected_success[] = "Usage: arp [OPTION...]\n\
> +\n\
> +  -?, --help                 Give this help list\n\
> +      --usage                Give a short usage message\n\
> +\n\
> +this is post_doc\n\
> +";
> +char *argv[3] = { (char *) "arp", NULL, NULL };
> +
> +static void
> +do_test_call (void)
> +{
> +  static char doc[] = "\vthis is post_doc";
> +  static struct argp argp = {NULL, NULL, NULL, doc};
> +
> +  argp_parse (&argp, 2, argv, 0, 0, NULL);
> +}
> +
> +static int
> +do_one_test (const char *expected)
> +{
> +  struct support_capture_subprocess result;
> +  result = support_capture_subprocess ((void *) &do_test_call, NULL);
> +
> +  TEST_COMPARE_STRING (result.out.buffer, expected);
> +
> +  return 0;
> +}
> +
> +
> +static int
> +do_test (void)
> +{
> +  const char *argument = "--help";
> +  argv[1] = (char *)argument;
> +  // success condition
> +  do_one_test (expected_success);
> +  return 0;
> +}
> +
> +/* This file references do_test above and contains the definition of
> +   the main function.  */
> +#include <support/test-driver.c>
> +
> --
> 2.21.1
  

Thanks DJ for the review.

On Sat, Mar 21, 2020 at 7:33 AM DJ Delorie <dj@redhat.com> wrote:
>
> Girish Joshi <girish946@gmail.com> writes:
> > +        if ((!vt && !child) || (text == inp_text && !first_only))
>
> I stared at this code for a long time, and I'm still not sure I
> understand it.  I think that means the code is wrong, even if it does
> the right thing.
>
> The original bug has the root cause:
>
>  "When processing what should come before the '\v', this section sets
>   inp_text = doc and inp_text_limit = 0. That value of inp_text_limit is
>   interpreted later to mean "print the whole string."
>
> Would the logic be easier to follow if you just initialized
> inp_text_limit to -1 and have -1 mean "print the whole string"?  That
> way a value of zero is unambiguously an empty string.
>

I see your point.

> You'd end up with code like this:
>
> >   size_t inp_text_limit = -1;
>
> >   inp_text_limit = (!post && vt) ? (vt - doc) : -1;
>
> >   if (text == inp_text && inp_text_limit != -1)
>

I tried this, it does work properly.
I'll create and post a patch with these changes tomorrow.
Thanks again for the input.

Girish Joshi
  

Posting the corrected patch.

From 47f3274930fa57b238a182ea92f64117bae76df0 Mon Sep 17 00:00:00 2001
From: Girish Joshi <girish946@gmail.com>
Date: Thu, 7 May 2020 12:53:06 +0530
Subject: [PATCH] argp/argp-help.c: Corrected the default value and usage for
 inp_text_limit in argp_doc(). argp/tst-argp3.c: added test case when the doc
 string contains leading \v. argp/Makefile: added tst-argp3 to tests

Overview:
argp.doc prints incorrectly when it starts with '\v'.
In argp-help.c in the function argp_doc() variable inp_text_limit is reset to 0
if the doc string starts with '\v'. Which causes the whole doc string to be
printed in the case of pre documentation, because of initialization of inp_text
and inp_text_limit

    inp_text = post ? (vt ? vt + 1 : 0) : doc;
    inp_text_limit = (!post && vt) ? (vt - doc) : 0;

and the condition where the doc string is printed.

    if (text == inp_text && inp_text_limit)
      __argp_fmtstream_write (stream, inp_text, inp_text_limit);

So for the following code

    #include<argp.h>

    static char doc[] = "\vthis is post_doc";
    static struct argp argp = {NULL, NULL, NULL, doc};

    int main(int argc, char *args[]){
         argp_parse(&argp, argc, args, 0, 0, NULL);
    }

the output is

    $ argp-help --help
    Usage: argp-help [OPTION...]

    this is post_doc

      -?, --help                 Give this help list
          --usage                Give a short usage message

    this is post_doc

As mentioned in the bugzilla entry the first occurrence of
"this is post_doc" is erroneous as it is the pre doc and there is nothing
in the doc string in predoc section.

Implementation:
Reset the value of inp_text_limit to -1 if the doc string starts with '\v'.
Modify the condition for printing the complete doc string with validation for
inp_text_limit variable which looks like.

    if (text == inp_text && inp_text_limit != -1)
      __argp_fmtstream_write (stream, inp_text, inp_text_limit);

after this patch we get the output as following

    $ argp-help --help
    Usage: argp-help [OPTION...]

      -?, --help                 Give this help list
          --usage                Give a short usage message

    this is post_doc
---
 argp/Makefile    |  2 +-
 argp/argp-help.c |  6 ++---
 argp/tst-argp3.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+), 4 deletions(-)
 create mode 100644 argp/tst-argp3.c

diff --git a/argp/Makefile b/argp/Makefile
index 1f9b074bed..0c0270ffef 100644
--- a/argp/Makefile
+++ b/argp/Makefile
@@ -27,7 +27,7 @@ routines    = $(addprefix argp-, ba fmtstream
fs-xinl help parse pv \
                      pvh xinl eexst)

 tests        = argp-test tst-argp1 bug-argp1 tst-argp2 bug-argp2 \
-          tst-ldbl-argp
+          tst-ldbl-argp tst-argp3

 CFLAGS-argp-help.c += $(uses-callbacks) -fexceptions
 CFLAGS-argp-parse.c += $(uses-callbacks)
diff --git a/argp/argp-help.c b/argp/argp-help.c
index 2bcd6549fd..2aadbcb09e 100644
--- a/argp/argp-help.c
+++ b/argp/argp-help.c
@@ -1462,7 +1462,7 @@ argp_doc (const struct argp *argp, const struct
argp_state *state,
   const char *inp_text;
   void *input = 0;
   int anything = 0;
-  size_t inp_text_limit = 0;
+  size_t inp_text_limit = -1;
   const char *doc = dgettext (argp->argp_domain, argp->doc);
   const struct argp_child *child = argp->children;

@@ -1470,7 +1470,7 @@ argp_doc (const struct argp *argp, const struct
argp_state *state,
     {
       char *vt = strchr (doc, '\v');
       inp_text = post ? (vt ? vt + 1 : 0) : doc;
-      inp_text_limit = (!post && vt) ? (vt - doc) : 0;
+      inp_text_limit = (!post && vt) ? (vt - doc) : -1;
     }
   else
     inp_text = 0;
@@ -1496,7 +1496,7 @@ argp_doc (const struct argp *argp, const struct
argp_state *state,
       if (pre_blank)
     __argp_fmtstream_putc (stream, '\n');

-      if (text == inp_text && inp_text_limit)
+      if (text == inp_text && inp_text_limit != -1)
     __argp_fmtstream_write (stream, inp_text, inp_text_limit);
       else
     __argp_fmtstream_puts (stream, text);
diff --git a/argp/tst-argp3.c b/argp/tst-argp3.c
new file mode 100644
index 0000000000..cfdace2574
--- /dev/null
+++ b/argp/tst-argp3.c
@@ -0,0 +1,68 @@
+/* Test for argparse with leading '\v' in the doc string.
+  Copyright (C) 2020 Free Software Foundation, Inc.
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <https://www.gnu.org/licenses/>.*/
+
+
+#include<stdlib.h>
+#include<argp.h>
+
+#include <support/capture_subprocess.h>
+#include <support/check.h>
+
+
+static char expected_success[] = "Usage: arp [OPTION...]\n\
+\n\
+  -?, --help                 Give this help list\n\
+      --usage                Give a short usage message\n\
+\n\
+this is post_doc\n\
+";
+char *argv[3] = { (char *) "arp", NULL, NULL };
+
+static void
+do_test_call (void)
+{
+  static char doc[] = "\vthis is post_doc";
+  static struct argp argp = {NULL, NULL, NULL, doc};
+
+  argp_parse (&argp, 2, argv, 0, 0, NULL);
+}
+
+static int
+do_one_test (const char *expected)
+{
+  struct support_capture_subprocess result;
+  result = support_capture_subprocess ((void *) &do_test_call, NULL);
+
+  TEST_COMPARE_STRING (result.out.buffer, expected);
+
+  return 0;
+}
+
+
+static int
+do_test (void)
+{
+  const char *argument = "--help";
+  argv[1] = (char *)argument;
+  // success condition
+  do_one_test (expected_success);
+  return 0;
+}
+
+/* This file references do_test above and contains the definition of
+   the main function.  */
+#include <support/test-driver.c>
+
  

Ping.

Girish Joshi

On Fri, May 8, 2020 at 1:23 AM Girish Joshi <girish946@gmail.com> wrote:
>
> Posting the corrected patch.
>
> From 47f3274930fa57b238a182ea92f64117bae76df0 Mon Sep 17 00:00:00 2001
> From: Girish Joshi <girish946@gmail.com>
> Date: Thu, 7 May 2020 12:53:06 +0530
> Subject: [PATCH] argp/argp-help.c: Corrected the default value and usage for
>  inp_text_limit in argp_doc(). argp/tst-argp3.c: added test case when the doc
>  string contains leading \v. argp/Makefile: added tst-argp3 to tests
>
> Overview:
> argp.doc prints incorrectly when it starts with '\v'.
> In argp-help.c in the function argp_doc() variable inp_text_limit is reset to 0
> if the doc string starts with '\v'. Which causes the whole doc string to be
> printed in the case of pre documentation, because of initialization of inp_text
> and inp_text_limit
>
>     inp_text = post ? (vt ? vt + 1 : 0) : doc;
>     inp_text_limit = (!post && vt) ? (vt - doc) : 0;
>
> and the condition where the doc string is printed.
>
>     if (text == inp_text && inp_text_limit)
>       __argp_fmtstream_write (stream, inp_text, inp_text_limit);
>
> So for the following code
>
>     #include<argp.h>
>
>     static char doc[] = "\vthis is post_doc";
>     static struct argp argp = {NULL, NULL, NULL, doc};
>
>     int main(int argc, char *args[]){
>          argp_parse(&argp, argc, args, 0, 0, NULL);
>     }
>
> the output is
>
>     $ argp-help --help
>     Usage: argp-help [OPTION...]
>
>     this is post_doc
>
>       -?, --help                 Give this help list
>           --usage                Give a short usage message
>
>     this is post_doc
>
> As mentioned in the bugzilla entry the first occurrence of
> "this is post_doc" is erroneous as it is the pre doc and there is nothing
> in the doc string in predoc section.
>
> Implementation:
> Reset the value of inp_text_limit to -1 if the doc string starts with '\v'.
> Modify the condition for printing the complete doc string with validation for
> inp_text_limit variable which looks like.
>
>     if (text == inp_text && inp_text_limit != -1)
>       __argp_fmtstream_write (stream, inp_text, inp_text_limit);
>
> after this patch we get the output as following
>
>     $ argp-help --help
>     Usage: argp-help [OPTION...]
>
>       -?, --help                 Give this help list
>           --usage                Give a short usage message
>
>     this is post_doc
> ---
>  argp/Makefile    |  2 +-
>  argp/argp-help.c |  6 ++---
>  argp/tst-argp3.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 72 insertions(+), 4 deletions(-)
>  create mode 100644 argp/tst-argp3.c
>
> diff --git a/argp/Makefile b/argp/Makefile
> index 1f9b074bed..0c0270ffef 100644
> --- a/argp/Makefile
> +++ b/argp/Makefile
> @@ -27,7 +27,7 @@ routines    = $(addprefix argp-, ba fmtstream
> fs-xinl help parse pv \
>                       pvh xinl eexst)
>
>  tests        = argp-test tst-argp1 bug-argp1 tst-argp2 bug-argp2 \
> -          tst-ldbl-argp
> +          tst-ldbl-argp tst-argp3
>
>  CFLAGS-argp-help.c += $(uses-callbacks) -fexceptions
>  CFLAGS-argp-parse.c += $(uses-callbacks)
> diff --git a/argp/argp-help.c b/argp/argp-help.c
> index 2bcd6549fd..2aadbcb09e 100644
> --- a/argp/argp-help.c
> +++ b/argp/argp-help.c
> @@ -1462,7 +1462,7 @@ argp_doc (const struct argp *argp, const struct
> argp_state *state,
>    const char *inp_text;
>    void *input = 0;
>    int anything = 0;
> -  size_t inp_text_limit = 0;
> +  size_t inp_text_limit = -1;
>    const char *doc = dgettext (argp->argp_domain, argp->doc);
>    const struct argp_child *child = argp->children;
>
> @@ -1470,7 +1470,7 @@ argp_doc (const struct argp *argp, const struct
> argp_state *state,
>      {
>        char *vt = strchr (doc, '\v');
>        inp_text = post ? (vt ? vt + 1 : 0) : doc;
> -      inp_text_limit = (!post && vt) ? (vt - doc) : 0;
> +      inp_text_limit = (!post && vt) ? (vt - doc) : -1;
>      }
>    else
>      inp_text = 0;
> @@ -1496,7 +1496,7 @@ argp_doc (const struct argp *argp, const struct
> argp_state *state,
>        if (pre_blank)
>      __argp_fmtstream_putc (stream, '\n');
>
> -      if (text == inp_text && inp_text_limit)
> +      if (text == inp_text && inp_text_limit != -1)
>      __argp_fmtstream_write (stream, inp_text, inp_text_limit);
>        else
>      __argp_fmtstream_puts (stream, text);
> diff --git a/argp/tst-argp3.c b/argp/tst-argp3.c
> new file mode 100644
> index 0000000000..cfdace2574
> --- /dev/null
> +++ b/argp/tst-argp3.c
> @@ -0,0 +1,68 @@
> +/* Test for argparse with leading '\v' in the doc string.
> +  Copyright (C) 2020 Free Software Foundation, Inc.
> +
> +  This program is free software: you can redistribute it and/or modify
> +  it under the terms of the GNU General Public License as published by
> +  the Free Software Foundation; either version 3 of the License, or
> +  (at your option) any later version.
> +
> +  This program is distributed in the hope that it will be useful,
> +  but WITHOUT ANY WARRANTY; without even the implied warranty of
> +  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +  GNU General Public License for more details.
> +
> +  You should have received a copy of the GNU General Public License
> +  along with this program.  If not, see <https://www.gnu.org/licenses/>.*/
> +
> +
> +#include<stdlib.h>
> +#include<argp.h>
> +
> +#include <support/capture_subprocess.h>
> +#include <support/check.h>
> +
> +
> +static char expected_success[] = "Usage: arp [OPTION...]\n\
> +\n\
> +  -?, --help                 Give this help list\n\
> +      --usage                Give a short usage message\n\
> +\n\
> +this is post_doc\n\
> +";
> +char *argv[3] = { (char *) "arp", NULL, NULL };
> +
> +static void
> +do_test_call (void)
> +{
> +  static char doc[] = "\vthis is post_doc";
> +  static struct argp argp = {NULL, NULL, NULL, doc};
> +
> +  argp_parse (&argp, 2, argv, 0, 0, NULL);
> +}
> +
> +static int
> +do_one_test (const char *expected)
> +{
> +  struct support_capture_subprocess result;
> +  result = support_capture_subprocess ((void *) &do_test_call, NULL);
> +
> +  TEST_COMPARE_STRING (result.out.buffer, expected);
> +
> +  return 0;
> +}
> +
> +
> +static int
> +do_test (void)
> +{
> +  const char *argument = "--help";
> +  argv[1] = (char *)argument;
> +  // success condition
> +  do_one_test (expected_success);
> +  return 0;
> +}
> +
> +/* This file references do_test above and contains the definition of
> +   the main function.  */
> +#include <support/test-driver.c>
> +
> --
> 2.21.1
>
>
> Girish Joshi
> girishjoshi.io
  

Could someone please review this patch?

On Fri, May 8, 2020 at 1:23 AM Girish Joshi <girish946@gmail.com> wrote:
>
> Posting the corrected patch.
>
> From 47f3274930fa57b238a182ea92f64117bae76df0 Mon Sep 17 00:00:00 2001
> From: Girish Joshi <girish946@gmail.com>
> Date: Thu, 7 May 2020 12:53:06 +0530
> Subject: [PATCH] argp/argp-help.c: Corrected the default value and usage for
>  inp_text_limit in argp_doc(). argp/tst-argp3.c: added test case when the doc
>  string contains leading \v. argp/Makefile: added tst-argp3 to tests
>
> Overview:
> argp.doc prints incorrectly when it starts with '\v'.
> In argp-help.c in the function argp_doc() variable inp_text_limit is reset to 0
> if the doc string starts with '\v'. Which causes the whole doc string to be
> printed in the case of pre documentation, because of initialization of inp_text
> and inp_text_limit
>
>     inp_text = post ? (vt ? vt + 1 : 0) : doc;
>     inp_text_limit = (!post && vt) ? (vt - doc) : 0;
>
> and the condition where the doc string is printed.
>
>     if (text == inp_text && inp_text_limit)
>       __argp_fmtstream_write (stream, inp_text, inp_text_limit);
>
> So for the following code
>
>     #include<argp.h>
>
>     static char doc[] = "\vthis is post_doc";
>     static struct argp argp = {NULL, NULL, NULL, doc};
>
>     int main(int argc, char *args[]){
>          argp_parse(&argp, argc, args, 0, 0, NULL);
>     }
>
> the output is
>
>     $ argp-help --help
>     Usage: argp-help [OPTION...]
>
>     this is post_doc
>
>       -?, --help                 Give this help list
>           --usage                Give a short usage message
>
>     this is post_doc
>
> As mentioned in the bugzilla entry the first occurrence of
> "this is post_doc" is erroneous as it is the pre doc and there is nothing
> in the doc string in predoc section.
>
> Implementation:
> Reset the value of inp_text_limit to -1 if the doc string starts with '\v'.
> Modify the condition for printing the complete doc string with validation for
> inp_text_limit variable which looks like.
>
>     if (text == inp_text && inp_text_limit != -1)
>       __argp_fmtstream_write (stream, inp_text, inp_text_limit);
>
> after this patch we get the output as following
>
>     $ argp-help --help
>     Usage: argp-help [OPTION...]
>
>       -?, --help                 Give this help list
>           --usage                Give a short usage message
>
>     this is post_doc
> ---
>  argp/Makefile    |  2 +-
>  argp/argp-help.c |  6 ++---
>  argp/tst-argp3.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 72 insertions(+), 4 deletions(-)
>  create mode 100644 argp/tst-argp3.c
>
> diff --git a/argp/Makefile b/argp/Makefile
> index 1f9b074bed..0c0270ffef 100644
> --- a/argp/Makefile
> +++ b/argp/Makefile
> @@ -27,7 +27,7 @@ routines    = $(addprefix argp-, ba fmtstream
> fs-xinl help parse pv \
>                       pvh xinl eexst)
>
>  tests        = argp-test tst-argp1 bug-argp1 tst-argp2 bug-argp2 \
> -          tst-ldbl-argp
> +          tst-ldbl-argp tst-argp3
>
>  CFLAGS-argp-help.c += $(uses-callbacks) -fexceptions
>  CFLAGS-argp-parse.c += $(uses-callbacks)
> diff --git a/argp/argp-help.c b/argp/argp-help.c
> index 2bcd6549fd..2aadbcb09e 100644
> --- a/argp/argp-help.c
> +++ b/argp/argp-help.c
> @@ -1462,7 +1462,7 @@ argp_doc (const struct argp *argp, const struct
> argp_state *state,
>    const char *inp_text;
>    void *input = 0;
>    int anything = 0;
> -  size_t inp_text_limit = 0;
> +  size_t inp_text_limit = -1;
>    const char *doc = dgettext (argp->argp_domain, argp->doc);
>    const struct argp_child *child = argp->children;
>
> @@ -1470,7 +1470,7 @@ argp_doc (const struct argp *argp, const struct
> argp_state *state,
>      {
>        char *vt = strchr (doc, '\v');
>        inp_text = post ? (vt ? vt + 1 : 0) : doc;
> -      inp_text_limit = (!post && vt) ? (vt - doc) : 0;
> +      inp_text_limit = (!post && vt) ? (vt - doc) : -1;
>      }
>    else
>      inp_text = 0;
> @@ -1496,7 +1496,7 @@ argp_doc (const struct argp *argp, const struct
> argp_state *state,
>        if (pre_blank)
>      __argp_fmtstream_putc (stream, '\n');
>
> -      if (text == inp_text && inp_text_limit)
> +      if (text == inp_text && inp_text_limit != -1)
>      __argp_fmtstream_write (stream, inp_text, inp_text_limit);
>        else
>      __argp_fmtstream_puts (stream, text);
> diff --git a/argp/tst-argp3.c b/argp/tst-argp3.c
> new file mode 100644
> index 0000000000..cfdace2574
> --- /dev/null
> +++ b/argp/tst-argp3.c
> @@ -0,0 +1,68 @@
> +/* Test for argparse with leading '\v' in the doc string.
> +  Copyright (C) 2020 Free Software Foundation, Inc.
> +
> +  This program is free software: you can redistribute it and/or modify
> +  it under the terms of the GNU General Public License as published by
> +  the Free Software Foundation; either version 3 of the License, or
> +  (at your option) any later version.
> +
> +  This program is distributed in the hope that it will be useful,
> +  but WITHOUT ANY WARRANTY; without even the implied warranty of
> +  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +  GNU General Public License for more details.
> +
> +  You should have received a copy of the GNU General Public License
> +  along with this program.  If not, see <https://www.gnu.org/licenses/>.*/
> +
> +
> +#include<stdlib.h>
> +#include<argp.h>
> +
> +#include <support/capture_subprocess.h>
> +#include <support/check.h>
> +
> +
> +static char expected_success[] = "Usage: arp [OPTION...]\n\
> +\n\
> +  -?, --help                 Give this help list\n\
> +      --usage                Give a short usage message\n\
> +\n\
> +this is post_doc\n\
> +";
> +char *argv[3] = { (char *) "arp", NULL, NULL };
> +
> +static void
> +do_test_call (void)
> +{
> +  static char doc[] = "\vthis is post_doc";
> +  static struct argp argp = {NULL, NULL, NULL, doc};
> +
> +  argp_parse (&argp, 2, argv, 0, 0, NULL);
> +}
> +
> +static int
> +do_one_test (const char *expected)
> +{
> +  struct support_capture_subprocess result;
> +  result = support_capture_subprocess ((void *) &do_test_call, NULL);
> +
> +  TEST_COMPARE_STRING (result.out.buffer, expected);
> +
> +  return 0;
> +}
> +
> +
> +static int
> +do_test (void)
> +{
> +  const char *argument = "--help";
> +  argv[1] = (char *)argument;
> +  // success condition
> +  do_one_test (expected_success);
> +  return 0;
> +}
> +
> +/* This file references do_test above and contains the definition of
> +   the main function.  */
> +#include <support/test-driver.c>
> +
> --
> 2.21.1
>

Thanks.
Girish Joshi
  

* Girish Joshi via Libc-alpha:

> diff --git a/argp/Makefile b/argp/Makefile
> index 1f9b074bed..0c0270ffef 100644
> --- a/argp/Makefile
> +++ b/argp/Makefile
> @@ -27,7 +27,7 @@ routines    = $(addprefix argp-, ba fmtstream
> fs-xinl help parse pv \

This patch is malformed.  Please try reposting it as an attachment.
(I probably will not have time to look at this patch.)

Thanks,
Florian
  

> This patch is malformed.  Please try reposting it as an attachment.

reposting the patch.
Thanks.

Girish Joshi
  

I wanted to review this patch, but I don't know enough about argp to
do it, and I don't have time today to learn how it works.

argp is shared with gnulib ( https://www.gnu.org/software/gnulib/ ).
I would like to suggest that you post this patch to
bug-gnulib@gnu.org.  (Despite the name, this is the appropriate list
to send gnulib patches to.)  There may be people reading that list who
can review your patch, and their review will be good enough for us as
well.

zw
  

Hi,

For a long time I could not work on this patch.
Recently I had sent the patch on gnulib mailing list, but did not get
a reply yet.
I'll send another follow up mail over there also.
Also I saw a few patches involving argp on the glibc mailing list.
So I'm sending this patch once again. Could someone please review it?
Thanks.

Girish Joshi