[PATCH 0/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[PATCH 0/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Garima Singh via GitGitGadget]

Hey,

In [1], Junio described a potential bug in sq_quote_buf_pretty() when the
arg is a zero length string and how he believes the method should behave.
This commit teaches sq_quote_buf_pretty to emit '' for null and empty
strings.

Looking forward to your review. Cheers! Garima Singh

[1] 
https://public-inbox.org/git/pull.298.git.gitgitgadget@gmail.com/T/#m9e33936067ec2066f675aa63133a2486efd415fd

Garima Singh (1):
  quote: handle null and empty strings in sq_quote_buf_pretty()

 Makefile              |  1 +
 quote.c               |  9 +++++++
 t/helper/test-quote.c | 28 +++++++++++++++++++++
 t/helper/test-tool.c  |  1 +
 t/helper/test-tool.h  |  1 +
 t/t0091-quote.sh      | 58 +++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 98 insertions(+)
 create mode 100644 t/helper/test-quote.c
 create mode 100755 t/t0091-quote.sh


base-commit: 5fa0f5238b0cd46cfe7f6fa76c3f526ea98148d9
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-314%2Fgarimasi514%2FcoreGit-fixQuote-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-314/garimasi514/coreGit-fixQuote-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/314
-- 
gitgitgadget

[PATCH 1/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Garima Singh via GitGitGadget]

From: Garima Singh <garima.singh@microsoft.com>

In [1], Junio described a potential bug in sq_quote_buf_pretty() when the arg
is a zero length string. It should emit quote-quote rather than nothing.
This commit teaches sq_quote_buf_pretty to emit '' for null and empty strings.

[1] https://public-inbox.org/git/pull.298.git.gitgitgadget@gmail.com/T/#m9e33936067ec2066f675aa63133a2486efd415fd

Signed-off-by: Garima Singh <garima.singh@microsoft.com>
---
 Makefile              |  1 +
 quote.c               |  9 +++++++
 t/helper/test-quote.c | 28 +++++++++++++++++++++
 t/helper/test-tool.c  |  1 +
 t/helper/test-tool.h  |  1 +
 t/t0091-quote.sh      | 58 +++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 98 insertions(+)
 create mode 100644 t/helper/test-quote.c
 create mode 100755 t/t0091-quote.sh

diff --git a/Makefile b/Makefile
index f9255344ae..2d6a12db57 100644
--- a/Makefile
+++ b/Makefile
@@ -728,6 +728,7 @@ TEST_BUILTINS_OBJS += test-parse-options.o
 TEST_BUILTINS_OBJS += test-path-utils.o
 TEST_BUILTINS_OBJS += test-pkt-line.o
 TEST_BUILTINS_OBJS += test-prio-queue.o
+TEST_BUILTINS_OBJS += test-quote.o
 TEST_BUILTINS_OBJS += test-reach.o
 TEST_BUILTINS_OBJS += test-read-cache.o
 TEST_BUILTINS_OBJS += test-read-midx.o
diff --git a/quote.c b/quote.c
index 7f2aa6faa4..84f61380fc 100644
--- a/quote.c
+++ b/quote.c
@@ -48,6 +48,15 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
 	static const char ok_punct[] = "+,-./:=@_^";
 	const char *p;
 
+	/*
+	 * In case of null or empty tokens, add a '' to ensure we 
+	 * don't inadvertently drop those tokens
+	 */
+	if (!src || !*src) {
+		strbuf_addstr(dst, "''");
+		return;
+	}
+
 	for (p = src; *p; p++) {
 		if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
 			sq_quote_buf(dst, src);
diff --git a/t/helper/test-quote.c b/t/helper/test-quote.c
new file mode 100644
index 0000000000..0266cc4fec
--- /dev/null
+++ b/t/helper/test-quote.c
@@ -0,0 +1,28 @@
+#include "test-tool.h"
+#include "quote.h"
+#include "strbuf.h"
+#include "string.h"
+
+int cmd__quote_buf_pretty(int argc, const char **argv)
+{
+	struct strbuf buf_payload = STRBUF_INIT;
+
+	if (!argv[1]) {
+		strbuf_release(&buf_payload);
+		die("missing input string");
+	}
+
+	if (!strcmp(argv[1], "nullString"))
+		sq_quote_buf_pretty(&buf_payload, NULL);
+
+	else if (!*argv[1])
+		sq_quote_buf_pretty(&buf_payload, "");
+
+	else
+		sq_quote_buf_pretty(&buf_payload, argv[1]);
+	
+	/* Wrap the results in [] to make the test script more readable */
+	printf("[%s]\n", buf_payload.buf);
+	strbuf_release(&buf_payload);
+	return 0;
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index ce7e89028c..55ee1402dd 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -56,6 +56,7 @@ static struct test_cmd cmds[] = {
 	{ "sha1-array", cmd__sha1_array },
 	{ "sha256", cmd__sha256 },
 	{ "sigchain", cmd__sigchain },
+	{ "quote-buf-pretty", cmd__quote_buf_pretty },
 	{ "strcmp-offset", cmd__strcmp_offset },
 	{ "string-list", cmd__string_list },
 	{ "submodule-config", cmd__submodule_config },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index f805bb39ae..8c0affe89c 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -46,6 +46,7 @@ int cmd__sha1(int argc, const char **argv);
 int cmd__sha1_array(int argc, const char **argv);
 int cmd__sha256(int argc, const char **argv);
 int cmd__sigchain(int argc, const char **argv);
+int cmd__quote_buf_pretty(int argc, const char **argv);
 int cmd__strcmp_offset(int argc, const char **argv);
 int cmd__string_list(int argc, const char **argv);
 int cmd__submodule_config(int argc, const char **argv);
diff --git a/t/t0091-quote.sh b/t/t0091-quote.sh
new file mode 100755
index 0000000000..a5515973c7
--- /dev/null
+++ b/t/t0091-quote.sh
@@ -0,0 +1,58 @@
+#!/bin/sh
+
+test_description='Testing the sq_quote_buf_pretty method in quote.c'
+. ./test-lib.sh
+
+test_expect_success 'test method without input string' '
+	test_must_fail test-tool quote-buf-pretty
+'
+
+test_expect_success 'test null string' '
+	cat >expect <<-EOF &&
+	'[\'\']'
+	EOF
+	test-tool quote-buf-pretty nullString >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'test empty string' '
+	cat >expect <<-EOF &&
+	'[\'\']'
+	EOF
+	test-tool quote-buf-pretty "" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'string without any punctuation' '
+	cat >expect <<-EOF &&
+	[testString]
+	EOF
+	test-tool quote-buf-pretty testString >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'string with punctuation that do not require special quotes' '
+	cat >expect <<-EOF &&
+	[test+String]
+	EOF
+	test-tool quote-buf-pretty test+String >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'string with punctuation that requires special quotes' '
+	cat >expect <<-EOF &&
+	'[\'test~String\']'
+	EOF
+	test-tool quote-buf-pretty test~String >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'string with punctuation that requires special quotes' '
+	cat >expect <<-EOF &&
+	'[\'test\'\\!\'String\']'
+	EOF
+	test-tool quote-buf-pretty test!String >actual &&
+	test_cmp expect actual
+'
+
+test_done
-- 
gitgitgadget

Re: [PATCH 1/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Junio C Hamano]

"Garima Singh via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Garima Singh <garima.singh@microsoft.com>
>
> In [1], Junio described a potential bug in sq_quote_buf_pretty() when the arg
> is a zero length string. It should emit quote-quote rather than nothing.
> This commit teaches sq_quote_buf_pretty to emit '' for null and empty strings.
>
> [1] https://public-inbox.org/git/pull.298.git.gitgitgadget@gmail.com/T/#m9e33936067ec2066f675aa63133a2486efd415fd

It would be more helpful to omit "Junio described a bug" and say
what the bug is.  As written, people still need to go back the list
archive to read what I said in order to understand what bug was
noticed by me, but you can save their time by describing the bug
directly in the log message.  For example:

    The sq_quote_buf_pretty() function does not emit anything when
    the incoming string is empty, but the function is to accumulate
    command line arguments, properly quoted as necessary, and the
    right way to add an argument that is an empty string is to show
    it quoted, i.e. ''.

or something like that.  The credit to discoverer, if you must, can
be given with

    Reported-by: ...

before your sign-off, but I do not think it is worth the trouble
this time.

>  create mode 100644 t/helper/test-quote.c
>  create mode 100755 t/t0091-quote.sh

I do not appreciate these two new files only to test this corner
case.  That feels overly inefficient and unwieldy.  It also hides
the potential impact of the bug from readers to run *only* a unit
test by using the function directly from an invented, non-real-world
caller that is a program in t/helper/.  It sometimes cannot be
helped as some codepath is harder to trigger from the actual
codepath in Git that matters in the real-world and is OK to resort
to t/helper/ program, but in this particular case, with a little
effort, we can find a codepath that can be used to feed an empty
string to the function quite easily.

Here is what I did for example.

 $ git grep sq_quote_buf_pretty

tells me that sq_quote_quote_argv_pretty() calls it.

 $ git grep sq_quote_argv_pretty

then tells me that trace_run_command() makes a call to it.  This is
perfect, as we can have "git" run a command with arbitrary command
line args and have trace print what it did.

So...

 $ GIT_TRACE=1 git -c "alias.foo=frotz foo '' bar" foo
 13:19:51.999614 git.c:703               trace: exec: git-foo
 13:19:51.999695 run-command.c:663       trace: run_command: git-foo
 13:19:51.999963 git.c:384               trace: alias expansion: foo => frotz foo  bar
 13:19:52.000327 git.c:703               trace: exec: git-frotz foo  bar
 13:19:52.000348 run-command.c:663       trace: run_command: git-frotz foo  bar
 expansion of alias 'foo' failed; 'frotz' is not a git command

With the bug fixed, 

 $ GIT_TRACE=1 ./git -c "alias.foo=frotz foo '' bar" foo
 13:22:16.777692 git.c:670               trace: exec: git-foo
 13:22:16.777806 run-command.c:643       trace: run_command: git-foo
 13:22:16.778084 git.c:366               trace: alias expansion: foo => frotz foo '' bar
 13:22:16.778315 git.c:670               trace: exec: git-frotz foo '' bar
 13:22:16.778329 run-command.c:643       trace: run_command: git-frotz foo '' bar
 expansion of alias 'foo' failed; 'frotz' is not a git command

we can see that the second arg to git-frotz is prettily shown.

Re: [PATCH 1/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Junio C Hamano]

Junio C Hamano <gitster@pobox.com> writes:

> "Garima Singh via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
>>  create mode 100644 t/helper/test-quote.c
>>  create mode 100755 t/t0091-quote.sh
>
> I do not appreciate these two new files only to test this corner
> case.  ...

To avoid misunderstanding, I am not against having unit tests when
they are appropriate. What I am against is to have only unit tests,
especially when the effect of a bug (and its fix) can be tested with
externally observable behaviour. The latter gives us a better sense
of the real-world impact (e.g. if run_command would spawn the given
command via shell using the 'sh -c "... stringified command and its
arguments ..."' idiom, it may be done with the function we fixed
here, which would mean that the user cannot pass '' as an argument
to that codepath), while a unit test gives readers "ok, the function
behaves that way now" alone, without answering "then what?  What
difference does this fix make to my use of Git as a whole?".

In any case, thanks for an attempt to fix.

Re: [PATCH 1/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Junio C Hamano]

"Garima Singh via GitGitGadget" <gitgitgadget@gmail.com> writes:

> +	/*
> +	 * In case of null or empty tokens, add a '' to ensure we 
> +	 * don't inadvertently drop those tokens
> +	 */

A good comment.

> +	if (!src || !*src) {

I think a caller that passes src==NULL deserves a BUG, or just a
normal segfault.  The condition here should just be "if (!*src)"
instead.

> +		strbuf_addstr(dst, "''");
> +		return;
> +	}

Otherwise, the fix itself is good.

Thanks.


>  	for (p = src; *p; p++) {
>  		if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
>  			sq_quote_buf(dst, src);

[PATCH v2 0/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Garima Singh via GitGitGadget]

Hey,

The sq_quote_buf_pretty() function does not emit anything when the incoming
string is empty, but the function is to accumulate command line arguments,
properly quoted as necessary, and the right way to add an argument that is
an empty string is to show it quoted, i.e. ''.

Looking forward to your review. Cheers! Garima Singh

Reported by: Junio Hamano gitster@pobox.com [gitster@pobox.com] in
https://public-inbox.org/git/pull.298.git.gitgitgadget@gmail.com/T/#m9e33936067ec2066f675aa63133a2486efd415fd

Garima Singh (1):
  quote: handle null and empty strings in sq_quote_buf_pretty()

 quote.c          | 12 ++++++++++++
 t/t0014-alias.sh |  8 ++++++++
 2 files changed, 20 insertions(+)


base-commit: 5fa0f5238b0cd46cfe7f6fa76c3f526ea98148d9
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-314%2Fgarimasi514%2FcoreGit-fixQuote-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-314/garimasi514/coreGit-fixQuote-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/314

Range-diff vs v1:

 1:  9d2685bdb2 < -:  ---------- quote: handle null and empty strings in sq_quote_buf_pretty()
 -:  ---------- > 1:  b9a68598d7 quote: handle null and empty strings in sq_quote_buf_pretty()

-- 
gitgitgadget

[PATCH v2 1/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Garima Singh via GitGitGadget]

From: Garima Singh <garima.singh@microsoft.com>

The sq_quote_buf_pretty() function does not emit anything when
the incoming string is empty, but the function is to accumulate
command line arguments, properly quoted as necessary, and the
right way to add an argument that is an empty string is to show
it quoted, i.e. ''. We warn the caller with the BUG macro if they
pass in a NULL.

Reported by: Junio Hamano <gitster@pobox.com>
Signed-off-by: Garima Singh <garima.singh@microsoft.com>
---
 quote.c          | 12 ++++++++++++
 t/t0014-alias.sh |  8 ++++++++
 2 files changed, 20 insertions(+)

diff --git a/quote.c b/quote.c
index 7f2aa6faa4..6d0f8a22a9 100644
--- a/quote.c
+++ b/quote.c
@@ -48,6 +48,18 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
 	static const char ok_punct[] = "+,-./:=@_^";
 	const char *p;
 
+	/* In case of null tokens, warn the user of the BUG in their call. */
+	if (!src) 
+		BUG("BUG can't append a NULL token to the buffer");
+	
+	/* In case of empty tokens, add a '' to ensure they 
+	 * don't get inadvertently dropped. 
+	 */
+	if (!*src) {
+		strbuf_addstr(dst, "''");
+		return;
+	}
+
 	for (p = src; *p; p++) {
 		if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
 			sq_quote_buf(dst, src);
diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
index a070e645d7..9c176c7cbb 100755
--- a/t/t0014-alias.sh
+++ b/t/t0014-alias.sh
@@ -37,4 +37,12 @@ test_expect_success 'looping aliases - internal execution' '
 #	test_i18ngrep "^fatal: alias loop detected: expansion of" output
 #'
 
+test_expect_success 'run-command parses empty args properly, using sq_quote_buf_pretty' '
+	cat >expect <<-EOF &&
+	fatal: cannot change to '\''alias.foo=frotz foo '\'''\'' bar'\'': No such file or directory
+	EOF
+	test_expect_code 128 git -C "alias.foo=frotz foo '\'''\'' bar" foo 2>actual &&
+	test_cmp expect actual
+'
+
 test_done
-- 
gitgitgadget

Re: [PATCH v2 1/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Garima Singh]

Thanks for the review Junio! I really appreciate it and look forward
to hear what you think of the updated patch.

Cheers!
Garima Singh


On Mon, Aug 26, 2019 at 10:44 AM Garima Singh via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Garima Singh <garima.singh@microsoft.com>
>
> The sq_quote_buf_pretty() function does not emit anything when
> the incoming string is empty, but the function is to accumulate
> command line arguments, properly quoted as necessary, and the
> right way to add an argument that is an empty string is to show
> it quoted, i.e. ''. We warn the caller with the BUG macro if they
> pass in a NULL.
>
> Reported by: Junio Hamano <gitster@pobox.com>
> Signed-off-by: Garima Singh <garima.singh@microsoft.com>
> ---
>  quote.c          | 12 ++++++++++++
>  t/t0014-alias.sh |  8 ++++++++
>  2 files changed, 20 insertions(+)
>
> diff --git a/quote.c b/quote.c
> index 7f2aa6faa4..6d0f8a22a9 100644
> --- a/quote.c
> +++ b/quote.c
> @@ -48,6 +48,18 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
>         static const char ok_punct[] = "+,-./:=@_^";
>         const char *p;
>
> +       /* In case of null tokens, warn the user of the BUG in their call. */
> +       if (!src)
> +               BUG("BUG can't append a NULL token to the buffer");
> +
> +       /* In case of empty tokens, add a '' to ensure they
> +        * don't get inadvertently dropped.
> +        */
> +       if (!*src) {
> +               strbuf_addstr(dst, "''");
> +               return;
> +       }
> +
>         for (p = src; *p; p++) {
>                 if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
>                         sq_quote_buf(dst, src);
> diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
> index a070e645d7..9c176c7cbb 100755
> --- a/t/t0014-alias.sh
> +++ b/t/t0014-alias.sh
> @@ -37,4 +37,12 @@ test_expect_success 'looping aliases - internal execution' '
>  #      test_i18ngrep "^fatal: alias loop detected: expansion of" output
>  #'
>
> +test_expect_success 'run-command parses empty args properly, using sq_quote_buf_pretty' '
> +       cat >expect <<-EOF &&
> +       fatal: cannot change to '\''alias.foo=frotz foo '\'''\'' bar'\'': No such file or directory
> +       EOF
> +       test_expect_code 128 git -C "alias.foo=frotz foo '\'''\'' bar" foo 2>actual &&
> +       test_cmp expect actual
> +'
> +
>  test_done
> --
> gitgitgadget

Re: [PATCH v2 1/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Junio C Hamano]

Garima Singh <garimasigit@gmail.com> writes:

>> diff --git a/quote.c b/quote.c
>> index 7f2aa6faa4..6d0f8a22a9 100644
>> --- a/quote.c
>> +++ b/quote.c
>> @@ -48,6 +48,18 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
>>         static const char ok_punct[] = "+,-./:=@_^";
>>         const char *p;
>>
>> +       /* In case of null tokens, warn the user of the BUG in their call. */
>> +       if (!src)
>> +               BUG("BUG can't append a NULL token to the buffer");

I thought that the BUG() macro already says "BUG" upfront, no?

Dereferencing to see if we have an empty string below will
immediately give us segfault, so I would omit this check if I were
writing this code, though.

>> +       /* In case of empty tokens, add a '' to ensure they
>> +        * don't get inadvertently dropped.
>> +        */

Our multi-line comments have the opening slash-asterisk and the
closing asterisk-slash on their own lines.

But more importantly, "In case of empty tokens, add a ''" in this
comment has zero information contents---you can read that from the
code.  Why we do that is what we cannot express in the code, and
deserves a comment.

	/* avoid losing a zero-length string by giving nothing */

or something like that, perhaps?

>> +       if (!*src) {
>> +               strbuf_addstr(dst, "''");
>> +               return;
>> +       }
>> +
>>         for (p = src; *p; p++) {
>>                 if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
>>                         sq_quote_buf(dst, src);
>> diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
>> index a070e645d7..9c176c7cbb 100755
>> --- a/t/t0014-alias.sh
>> +++ b/t/t0014-alias.sh
>> @@ -37,4 +37,12 @@ test_expect_success 'looping aliases - internal execution' '
>>  #      test_i18ngrep "^fatal: alias loop detected: expansion of" output
>>  #'
>>
>> +test_expect_success 'run-command parses empty args properly, using sq_quote_buf_pretty' '
>> +       cat >expect <<-EOF &&
>> +       fatal: cannot change to '\''alias.foo=frotz foo '\'''\'' bar'\'': No such file or directory
>> +       EOF
>> +       test_expect_code 128 git -C "alias.foo=frotz foo '\'''\'' bar" foo 2>actual &&
>> +       test_cmp expect actual
>> +'

I think it was my mistake, but we do not ahe to use "alias" for
something like this, perhaps like:

    # 'git frotz' will fail with "no such command", but we are
    # not interested in its exit status.  We just want to see
    # how sq_quote_argv_pretty() shows arguments in the trace.
    GIT_TRACE=1 git frotz a "" b " " c 2>&1 |
    sed -ne "/run_command:/s/.*trace: run_command: //p" >actual &&
    echo "git-frotz a '' b ' ' c" >expect &&
    test_cmp expect actual

>> +
>>  test_done
>> --
>> gitgitgadget

[PATCH v3 0/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Garima Singh via GitGitGadget]

Hey,

The sq_quote_buf_pretty() function does not emit anything when the incoming
string is empty, but the function is to accumulate command line arguments,
properly quoted as necessary, and the right way to add an argument that is
an empty string is to show it quoted, i.e. ''.

Looking forward to your review. Cheers! Garima Singh

Reported by: Junio Hamano gitster@pobox.com [gitster@pobox.com] in
https://public-inbox.org/git/pull.298.git.gitgitgadget@gmail.com/T/#m9e33936067ec2066f675aa63133a2486efd415fd

Garima Singh (1):
  quote: handle numm and empty strings in sq_quote_buf_pretty

 quote.c          | 10 ++++++++++
 t/t0014-alias.sh |  7 +++++++
 2 files changed, 17 insertions(+)


base-commit: 5fa0f5238b0cd46cfe7f6fa76c3f526ea98148d9
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-314%2Fgarimasi514%2FcoreGit-fixQuote-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-314/garimasi514/coreGit-fixQuote-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/314

Range-diff vs v2:

 1:  b9a68598d7 ! 1:  399fe02cb1 quote: handle null and empty strings in sq_quote_buf_pretty()
     @@ -1,13 +1,13 @@
      Author: Garima Singh <garima.singh@microsoft.com>
      
     -    quote: handle null and empty strings in sq_quote_buf_pretty()
     +    quote: handle numm and empty strings in sq_quote_buf_pretty
      
     -    The sq_quote_buf_pretty() function does not emit anything when
     -    the incoming string is empty, but the function is to accumulate
     -    command line arguments, properly quoted as necessary, and the
     -    right way to add an argument that is an empty string is to show
     -    it quoted, i.e. ''. We warn the caller with the BUG macro if they
     -    pass in a NULL.
     +    The sq_quote_buf_pretty() function does not emit anything
     +    when the incoming string is empty, but the function is to
     +    accumulate command line arguments, properly quoted as
     +    necessary, and the right way to add an argument that is an
     +    empty string is to show it quoted, i.e. ''. We warn the caller
     +    with the BUG macro is they pass in a NULL.
      
          Reported by: Junio Hamano <gitster@pobox.com>
          Signed-off-by: Garima Singh <garima.singh@microsoft.com>
     @@ -21,11 +21,9 @@
       
      +	/* In case of null tokens, warn the user of the BUG in their call. */
      +	if (!src) 
     -+		BUG("BUG can't append a NULL token to the buffer");
     ++		BUG("Cannot append a NULL token to the buffer");
      +	
     -+	/* In case of empty tokens, add a '' to ensure they 
     -+	 * don't get inadvertently dropped. 
     -+	 */
     ++	/* Avoid dropping a zero-length token by adding '' */
      +	if (!*src) {
      +		strbuf_addstr(dst, "''");
      +		return;
     @@ -43,11 +41,10 @@
       #'
       
      +test_expect_success 'run-command parses empty args properly, using sq_quote_buf_pretty' '
     -+	cat >expect <<-EOF &&
     -+	fatal: cannot change to '\''alias.foo=frotz foo '\'''\'' bar'\'': No such file or directory
     -+	EOF
     -+	test_expect_code 128 git -C "alias.foo=frotz foo '\'''\'' bar" foo 2>actual &&
     -+	test_cmp expect actual
     ++    GIT_TRACE=1 git frotz a "" b " " c 2>&1 |
     ++    sed -ne "/run_command:/s/.*trace: run_command: //p" >actual &&
     ++    echo "git-frotz a '\'''\'' b '\'' '\'' c" >expect &&
     ++    test_cmp expect actual
      +'
      +
       test_done

-- 
gitgitgadget

[PATCH v3 1/1] quote: handle numm and empty strings in sq_quote_buf_pretty

[Garima Singh via GitGitGadget]

From: Garima Singh <garima.singh@microsoft.com>

The sq_quote_buf_pretty() function does not emit anything
when the incoming string is empty, but the function is to
accumulate command line arguments, properly quoted as
necessary, and the right way to add an argument that is an
empty string is to show it quoted, i.e. ''. We warn the caller
with the BUG macro is they pass in a NULL.

Reported by: Junio Hamano <gitster@pobox.com>
Signed-off-by: Garima Singh <garima.singh@microsoft.com>
---
 quote.c          | 10 ++++++++++
 t/t0014-alias.sh |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/quote.c b/quote.c
index 7f2aa6faa4..f31ebf6c43 100644
--- a/quote.c
+++ b/quote.c
@@ -48,6 +48,16 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
 	static const char ok_punct[] = "+,-./:=@_^";
 	const char *p;
 
+	/* In case of null tokens, warn the user of the BUG in their call. */
+	if (!src) 
+		BUG("Cannot append a NULL token to the buffer");
+	
+	/* Avoid dropping a zero-length token by adding '' */
+	if (!*src) {
+		strbuf_addstr(dst, "''");
+		return;
+	}
+
 	for (p = src; *p; p++) {
 		if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
 			sq_quote_buf(dst, src);
diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
index a070e645d7..ae316aa6fd 100755
--- a/t/t0014-alias.sh
+++ b/t/t0014-alias.sh
@@ -37,4 +37,11 @@ test_expect_success 'looping aliases - internal execution' '
 #	test_i18ngrep "^fatal: alias loop detected: expansion of" output
 #'
 
+test_expect_success 'run-command parses empty args properly, using sq_quote_buf_pretty' '
+    GIT_TRACE=1 git frotz a "" b " " c 2>&1 |
+    sed -ne "/run_command:/s/.*trace: run_command: //p" >actual &&
+    echo "git-frotz a '\'''\'' b '\'' '\'' c" >expect &&
+    test_cmp expect actual
+'
+
 test_done
-- 
gitgitgadget

Re: [PATCH v3 1/1] quote: handle numm and empty strings in sq_quote_buf_pretty

[Garima Singh]

I just noticed the typo in the commit message in my latest update.
Sorry about that. 
Junio, would you be willing to fix it up whenever you queue the patch?
Or would you like me to send another update. 

Thanks
Garima G Singh

On 10/7/2019 12:17 PM, Garima Singh via GitGitGadget wrote:
> From: Garima Singh <garima.singh@microsoft.com>
> 
> The sq_quote_buf_pretty() function does not emit anything
> when the incoming string is empty, but the function is to
> accumulate command line arguments, properly quoted as
> necessary, and the right way to add an argument that is an
> empty string is to show it quoted, i.e. ''. We warn the caller
> with the BUG macro is they pass in a NULL.
> 
> Reported by: Junio Hamano <gitster@pobox.com>
> Signed-off-by: Garima Singh <garima.singh@microsoft.com>
> ---
>  quote.c          | 10 ++++++++++
>  t/t0014-alias.sh |  7 +++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/quote.c b/quote.c
> index 7f2aa6faa4..f31ebf6c43 100644
> --- a/quote.c
> +++ b/quote.c
> @@ -48,6 +48,16 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
>  	static const char ok_punct[] = "+,-./:=@_^";
>  	const char *p;
>  
> +	/* In case of null tokens, warn the user of the BUG in their call. */
> +	if (!src) 
> +		BUG("Cannot append a NULL token to the buffer");
> +	
> +	/* Avoid dropping a zero-length token by adding '' */
> +	if (!*src) {
> +		strbuf_addstr(dst, "''");
> +		return;
> +	}
> +
>  	for (p = src; *p; p++) {
>  		if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
>  			sq_quote_buf(dst, src);
> diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
> index a070e645d7..ae316aa6fd 100755
> --- a/t/t0014-alias.sh
> +++ b/t/t0014-alias.sh
> @@ -37,4 +37,11 @@ test_expect_success 'looping aliases - internal execution' '
>  #	test_i18ngrep "^fatal: alias loop detected: expansion of" output
>  #'
>  
> +test_expect_success 'run-command parses empty args properly, using sq_quote_buf_pretty' '
> +    GIT_TRACE=1 git frotz a "" b " " c 2>&1 |
> +    sed -ne "/run_command:/s/.*trace: run_command: //p" >actual &&
> +    echo "git-frotz a '\'''\'' b '\'' '\'' c" >expect &&
> +    test_cmp expect actual
> +'
> +
>  test_done
> 

Re: [PATCH v3 1/1] quote: handle numm and empty strings in sq_quote_buf_pretty

[Eric Sunshine]

On Mon, Oct 7, 2019 at 12:17 PM Garima Singh via GitGitGadget
<gitgitgadget@gmail.com> wrote:
> quote: handle numm and empty strings in sq_quote_buf_pretty

What is "numm"?

What does it mean to "handle" these things? A possible rewrite of the
subject to explain the problem more precisely rather than using
generalizations might be:

    sq_quote_buf_pretty: don't drop empty arguments

> The sq_quote_buf_pretty() function does not emit anything
> when the incoming string is empty, but the function is to
> accumulate command line arguments, properly quoted as
> necessary, and the right way to add an argument that is an
> empty string is to show it quoted, i.e. ''. We warn the caller
> with the BUG macro is they pass in a NULL.

s/is they/if they/

By including the final sentence in this paragraph, the reader is
confused into thinking that warning the caller with BUG() is the
overall purpose of this patch and is the "fix" for the stated problem.
At minimum, the final sentence should be yanked out to its own
paragraph or, better yet, dropped altogether since it's of little
importance in the overall scheme of the patch.

As a reader of this commit message, I find it difficult to understand
what problem it's trying to solve since the problem and solution and
existing behavior are presented in a circuitous way which doesn't make
any of them stand out clearly. Here's a possible rewrite:

    sq_quote_buf_pretty: don't drop empty arguments

    Empty arguments passed on a command-line should be represented by
    a zero-length quoted string, however, sq_quote_buf_pretty()
    incorrectly drops these arguments altogether. Fix this problem by
    ensuring that such arguments are emitted as '' instead.

> Reported by: Junio Hamano <gitster@pobox.com>
> Signed-off-by: Garima Singh <garima.singh@microsoft.com>
> ---
> diff --git a/quote.c b/quote.c
> @@ -48,6 +48,16 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
> +       /* In case of null tokens, warn the user of the BUG in their call. */
> +       if (!src)
> +               BUG("Cannot append a NULL token to the buffer");

The comment merely repeats what the code itself already says clearly,
thus adds no value and ought to be dropped.

Moreover, this entire check seems superfluous since the program will
crash anyhow as soon as 'src' is dereferenced (just below), thus the
programmer will find out soon enough about the error. I'd suggest
dropping this check entirely since it's not adding any value.

> +       /* Avoid dropping a zero-length token by adding '' */
> +       if (!*src) {
> +               strbuf_addstr(dst, "''");
> +               return;
> +       }

Ditto regarding dropping the useless comment which merely repeats what
the code itself already says clearly.

> diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
> @@ -37,4 +37,11 @@ test_expect_success 'looping aliases - internal execution' '
> +test_expect_success 'run-command parses empty args properly, using sq_quote_buf_pretty' '

Is "parses" the correct word? Should it be "formats" or something?

Also, the bit about "using sq_quote_buf_pretty" lets an implementation
detail bleed unnecessarily into the test suite, and that detail could
become outdated at some point (say, if some function ever replaces
that one, for instance). It should be sufficient for the test title
merely to mention that it is checking that empty arguments are handled
properly. So, perhaps:

    test_expect_success 'run-command formats empty args properly' '

> +    GIT_TRACE=1 git frotz a "" b " " c 2>&1 |
> +    sed -ne "/run_command:/s/.*trace: run_command: //p" >actual &&
> +    echo "git-frotz a '\'''\'' b '\'' '\'' c" >expect &&
> +    test_cmp expect actual
> +'

Re: [PATCH v3 1/1] quote: handle numm and empty strings in sq_quote_buf_pretty

[Garima Singh]

On 10/7/2019 1:27 PM, Eric Sunshine wrote:
> On Mon, Oct 7, 2019 at 12:17 PM Garima Singh via GitGitGadget
> <gitgitgadget@gmail.com> wrote:
>> quote: handle numm and empty strings in sq_quote_buf_pretty
> 
> What is "numm"?

Typo. Fixing in next update. 

> What does it mean to "handle" these things? A possible rewrite of the
> subject to explain the problem more precisely rather than using
> generalizations might be:
> 
>     sq_quote_buf_pretty: don't drop empty arguments
> 
>> The sq_quote_buf_pretty() function does not emit anything
>> when the incoming string is empty, but the function is to
>> accumulate command line arguments, properly quoted as
>> necessary, and the right way to add an argument that is an
>> empty string is to show it quoted, i.e. ''. We warn the caller
>> with the BUG macro is they pass in a NULL.
> 
> s/is they/if they/

Typo. Fixing in next update. 

> By including the final sentence in this paragraph, the reader is
> confused into thinking that warning the caller with BUG() is the
> overall purpose of this patch and is the "fix" for the stated problem.
> At minimum, the final sentence should be yanked out to its own
> paragraph or, better yet, dropped altogether since it's of little
> importance in the overall scheme of the patch.
> 
> As a reader of this commit message, I find it difficult to understand
> what problem it's trying to solve since the problem and solution and
> existing behavior are presented in a circuitous way which doesn't make
> any of them stand out clearly. Here's a possible rewrite:
> 
>     sq_quote_buf_pretty: don't drop empty arguments
> 
>     Empty arguments passed on a command-line should be represented by
>     a zero-length quoted string, however, sq_quote_buf_pretty()
>     incorrectly drops these arguments altogether. Fix this problem by
>     ensuring that such arguments are emitted as '' instead.

Works for me. Thanks! 

>> Reported by: Junio Hamano <gitster@pobox.com>
>> Signed-off-by: Garima Singh <garima.singh@microsoft.com>
>> ---
>> diff --git a/quote.c b/quote.c
>> @@ -48,6 +48,16 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
>> +       /* In case of null tokens, warn the user of the BUG in their call. */
>> +       if (!src)
>> +               BUG("Cannot append a NULL token to the buffer");
> 
> The comment merely repeats what the code itself already says clearly,
> thus adds no value and ought to be dropped.
> 
> Moreover, this entire check seems superfluous since the program will
> crash anyhow as soon as 'src' is dereferenced (just below), thus the
> programmer will find out soon enough about the error. I'd suggest
> dropping this check entirely since it's not adding any value.
> 

Fair enough. Removing the comment. Leaving the check. I would
rather the caller of the function know what went wrong instead
of a segfault. 

>> diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
>> @@ -37,4 +37,11 @@ test_expect_success 'looping aliases - internal execution' '
>> +test_expect_success 'run-command parses empty args properly, using sq_quote_buf_pretty' '
> 
> Is "parses" the correct word? Should it be "formats" or something?
> 
Sure. 

> Also, the bit about "using sq_quote_buf_pretty" lets an implementation
> detail bleed unnecessarily into the test suite, and that detail could
> become outdated at some point (say, if some function ever replaces
> that one, for instance). It should be sufficient for the test title
> merely to mention that it is checking that empty arguments are handled
> properly. So, perhaps:
> 
>     test_expect_success 'run-command formats empty args properly' '
> 

Sure. 

[PATCH v4 0/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Garima Singh via GitGitGadget]

Hey,

Empty arguments passed on the command line can be a represented by a '',
however sq_quote_buf_pretty was incorrectly dropping these arguments
altogether. Fix this problem by ensuring that such arguments are emitted as
'' instead.

Looking forward to your review. Cheers! Garima Singh

Reported by: Junio Hamano gitster@pobox.com [gitster@pobox.com] in
https://public-inbox.org/git/pull.298.git.gitgitgadget@gmail.com/T/#m9e33936067ec2066f675aa63133a2486efd415fd

Garima Singh (1):
  sq_quote_buf_pretty: don't drop empty arguments

 quote.c          | 9 +++++++++
 t/t0014-alias.sh | 7 +++++++
 2 files changed, 16 insertions(+)


base-commit: 5fa0f5238b0cd46cfe7f6fa76c3f526ea98148d9
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-314%2Fgarimasi514%2FcoreGit-fixQuote-v4
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-314/garimasi514/coreGit-fixQuote-v4
Pull-Request: https://github.com/gitgitgadget/git/pull/314

Range-diff vs v3:

 1:  399fe02cb1 ! 1:  a6a0217ce6 quote: handle numm and empty strings in sq_quote_buf_pretty
     @@ -1,13 +1,11 @@
      Author: Garima Singh <garima.singh@microsoft.com>
      
     -    quote: handle numm and empty strings in sq_quote_buf_pretty
     +    sq_quote_buf_pretty: don't drop empty arguments
      
     -    The sq_quote_buf_pretty() function does not emit anything
     -    when the incoming string is empty, but the function is to
     -    accumulate command line arguments, properly quoted as
     -    necessary, and the right way to add an argument that is an
     -    empty string is to show it quoted, i.e. ''. We warn the caller
     -    with the BUG macro is they pass in a NULL.
     +    Empty arguments passed on the command line can be a represented by
     +    a '', however sq_quote_buf_pretty was incorrectly dropping these
     +    arguments altogether. Fix this problem by ensuring that such
     +    arguments are emitted as '' instead.
      
          Reported by: Junio Hamano <gitster@pobox.com>
          Signed-off-by: Garima Singh <garima.singh@microsoft.com>
     @@ -19,11 +17,10 @@
       	static const char ok_punct[] = "+,-./:=@_^";
       	const char *p;
       
     -+	/* In case of null tokens, warn the user of the BUG in their call. */
      +	if (!src) 
      +		BUG("Cannot append a NULL token to the buffer");
      +	
     -+	/* Avoid dropping a zero-length token by adding '' */
     ++	/* Avoid losing a zero-length string by adding '' */ 
      +	if (!*src) {
      +		strbuf_addstr(dst, "''");
      +		return;
     @@ -40,7 +37,7 @@
       #	test_i18ngrep "^fatal: alias loop detected: expansion of" output
       #'
       
     -+test_expect_success 'run-command parses empty args properly, using sq_quote_buf_pretty' '
     ++test_expect_success 'run-command formats empty args properly' '
      +    GIT_TRACE=1 git frotz a "" b " " c 2>&1 |
      +    sed -ne "/run_command:/s/.*trace: run_command: //p" >actual &&
      +    echo "git-frotz a '\'''\'' b '\'' '\'' c" >expect &&

-- 
gitgitgadget

[PATCH v4 1/1] sq_quote_buf_pretty: don't drop empty arguments

[Garima Singh via GitGitGadget]

From: Garima Singh <garima.singh@microsoft.com>

Empty arguments passed on the command line can be a represented by
a '', however sq_quote_buf_pretty was incorrectly dropping these
arguments altogether. Fix this problem by ensuring that such
arguments are emitted as '' instead.

Reported by: Junio Hamano <gitster@pobox.com>
Signed-off-by: Garima Singh <garima.singh@microsoft.com>
---
 quote.c          | 9 +++++++++
 t/t0014-alias.sh | 7 +++++++
 2 files changed, 16 insertions(+)

diff --git a/quote.c b/quote.c
index 7f2aa6faa4..26f1848dde 100644
--- a/quote.c
+++ b/quote.c
@@ -48,6 +48,15 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
 	static const char ok_punct[] = "+,-./:=@_^";
 	const char *p;
 
+	if (!src) 
+		BUG("Cannot append a NULL token to the buffer");
+	
+	/* Avoid losing a zero-length string by adding '' */ 
+	if (!*src) {
+		strbuf_addstr(dst, "''");
+		return;
+	}
+
 	for (p = src; *p; p++) {
 		if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
 			sq_quote_buf(dst, src);
diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
index a070e645d7..2694c81afd 100755
--- a/t/t0014-alias.sh
+++ b/t/t0014-alias.sh
@@ -37,4 +37,11 @@ test_expect_success 'looping aliases - internal execution' '
 #	test_i18ngrep "^fatal: alias loop detected: expansion of" output
 #'
 
+test_expect_success 'run-command formats empty args properly' '
+    GIT_TRACE=1 git frotz a "" b " " c 2>&1 |
+    sed -ne "/run_command:/s/.*trace: run_command: //p" >actual &&
+    echo "git-frotz a '\'''\'' b '\'' '\'' c" >expect &&
+    test_cmp expect actual
+'
+
 test_done
-- 
gitgitgadget

Re: [PATCH v4 1/1] sq_quote_buf_pretty: don't drop empty arguments

[Junio C Hamano]

"Garima Singh via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Garima Singh <garima.singh@microsoft.com>
>
> Empty arguments passed on the command line can be a represented by
> a '', however sq_quote_buf_pretty was incorrectly dropping these
> arguments altogether. Fix this problem by ensuring that such
> arguments are emitted as '' instead.
>
> Reported by: Junio Hamano <gitster@pobox.com>
> Signed-off-by: Garima Singh <garima.singh@microsoft.com>
> ---
>  quote.c          | 9 +++++++++
>  t/t0014-alias.sh | 7 +++++++
>  2 files changed, 16 insertions(+)
>
> diff --git a/quote.c b/quote.c
> index 7f2aa6faa4..26f1848dde 100644
> --- a/quote.c
> +++ b/quote.c
> @@ -48,6 +48,15 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
>  	static const char ok_punct[] = "+,-./:=@_^";
>  	const char *p;
>  
> +	if (!src) 
> +		BUG("Cannot append a NULL token to the buffer");

Remove these two lines.

I do not want to see "if (!ptr) BUG("don't give a NULL pointer")"
sprinkled to every function that takes a pointer that must not be
NULL.  Any caller that violates the contract with the callee
deserves a segfault, so let's leave it at that.

> +	/* Avoid losing a zero-length string by adding '' */ 
> +	if (!*src) {
> +		strbuf_addstr(dst, "''");
> +		return;
> +	}
> +

Nice.

>  	for (p = src; *p; p++) {
>  		if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
>  			sq_quote_buf(dst, src);
> diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
> index a070e645d7..2694c81afd 100755
> --- a/t/t0014-alias.sh
> +++ b/t/t0014-alias.sh
> @@ -37,4 +37,11 @@ test_expect_success 'looping aliases - internal execution' '
>  #	test_i18ngrep "^fatal: alias loop detected: expansion of" output
>  #'
>  
> +test_expect_success 'run-command formats empty args properly' '
> +    GIT_TRACE=1 git frotz a "" b " " c 2>&1 |
> +    sed -ne "/run_command:/s/.*trace: run_command: //p" >actual &&
> +    echo "git-frotz a '\'''\'' b '\'' '\'' c" >expect &&
> +    test_cmp expect actual
> +'
> +
>  test_done

[PATCH v5 0/1] quote: handle null and empty strings in sq_quote_buf_pretty()

[Garima Singh via GitGitGadget]

Hey,

Empty arguments passed on the command line can be a represented by a '',
however sq_quote_buf_pretty was incorrectly dropping these arguments
altogether. Fix this problem by ensuring that such arguments are emitted as
'' instead.

Looking forward to your review. Cheers! Garima Singh

Reported by: Junio Hamano gitster@pobox.com [gitster@pobox.com] in
https://public-inbox.org/git/pull.298.git.gitgitgadget@gmail.com/T/#m9e33936067ec2066f675aa63133a2486efd415fd

Garima Singh (1):
  sq_quote_buf_pretty: don't drop empty arguments

 quote.c          | 6 ++++++
 t/t0014-alias.sh | 7 +++++++
 2 files changed, 13 insertions(+)


base-commit: 5fa0f5238b0cd46cfe7f6fa76c3f526ea98148d9
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-314%2Fgarimasi514%2FcoreGit-fixQuote-v5
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-314/garimasi514/coreGit-fixQuote-v5
Pull-Request: https://github.com/gitgitgadget/git/pull/314

Range-diff vs v4:

 1:  a6a0217ce6 ! 1:  412626ccf9 sq_quote_buf_pretty: don't drop empty arguments
     @@ -17,9 +17,6 @@
       	static const char ok_punct[] = "+,-./:=@_^";
       	const char *p;
       
     -+	if (!src) 
     -+		BUG("Cannot append a NULL token to the buffer");
     -+	
      +	/* Avoid losing a zero-length string by adding '' */ 
      +	if (!*src) {
      +		strbuf_addstr(dst, "''");

-- 
gitgitgadget

[PATCH v5 1/1] sq_quote_buf_pretty: don't drop empty arguments

[Garima Singh via GitGitGadget]

From: Garima Singh <garima.singh@microsoft.com>

Empty arguments passed on the command line can be a represented by
a '', however sq_quote_buf_pretty was incorrectly dropping these
arguments altogether. Fix this problem by ensuring that such
arguments are emitted as '' instead.

Reported by: Junio Hamano <gitster@pobox.com>
Signed-off-by: Garima Singh <garima.singh@microsoft.com>
---
 quote.c          | 6 ++++++
 t/t0014-alias.sh | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/quote.c b/quote.c
index 7f2aa6faa4..2d5d1c4360 100644
--- a/quote.c
+++ b/quote.c
@@ -48,6 +48,12 @@ void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
 	static const char ok_punct[] = "+,-./:=@_^";
 	const char *p;
 
+	/* Avoid losing a zero-length string by adding '' */ 
+	if (!*src) {
+		strbuf_addstr(dst, "''");
+		return;
+	}
+
 	for (p = src; *p; p++) {
 		if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
 			sq_quote_buf(dst, src);
diff --git a/t/t0014-alias.sh b/t/t0014-alias.sh
index a070e645d7..2694c81afd 100755
--- a/t/t0014-alias.sh
+++ b/t/t0014-alias.sh
@@ -37,4 +37,11 @@ test_expect_success 'looping aliases - internal execution' '
 #	test_i18ngrep "^fatal: alias loop detected: expansion of" output
 #'
 
+test_expect_success 'run-command formats empty args properly' '
+    GIT_TRACE=1 git frotz a "" b " " c 2>&1 |
+    sed -ne "/run_command:/s/.*trace: run_command: //p" >actual &&
+    echo "git-frotz a '\'''\'' b '\'' '\'' c" >expect &&
+    test_cmp expect actual
+'
+
 test_done
-- 
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