threads / patch / 5529

patchgitweb: reset input record separator in parse_commit even on error

Subject: [PATCH] gitweb: reset input record separator in parse_commit even on error

## tl;dr

3 messages between Sep 9, 2006 and Sep 9, 2006. Diffs are folded; open one to read it.

replies: 2people: 3as markdown or json

Sven Verdoolaege· Sep 9, 2006, 15:12 UTC · lore

--- This probably never happens, but just in case...

 gitweb/gitweb.perl |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Show changes to gitweb/gitweb.perl +1 −1

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 7afdf33..60dd598 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -897,8 +897,8 @@ sub parse_commit {
 		my $fd = git_pipe("rev-list", "--header", "--parents", "--max-count=1", $commit_id)
 			or return;
 		@commit_lines = split '\n', <$fd>;
-		close $fd or return;
 		$/ = "\n";
+		close $fd or return;
 		pop @commit_lines;
 	}
 	my $header = shift @commit_lines;

-- 
0.99.8c.g64e8-dirty

Jeff King· Sep 9, 2006, 20:51 UTC · re: Sven Verdoolaege · lore

Re: [PATCH] gitweb: reset input record separator in parse_commit even on error

On Sat, Sep 09, 2006 at 05:12:36PM +0200, Sven Verdoolaege wrote:

Show 14 quoted lines

> diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
> index 7afdf33..60dd598 100755
> --- a/gitweb/gitweb.perl
> +++ b/gitweb/gitweb.perl
> @@ -897,8 +897,8 @@ sub parse_commit {
>  		my $fd = git_pipe("rev-list", "--header", "--parents", "--max-count=1", $commit_id)
>  			or return;
>  		@commit_lines = split '\n', <$fd>;
> -		close $fd or return;
>  		$/ = "\n";
> +		close $fd or return;
>  		pop @commit_lines;
>  	}
>  	my $header = shift @commit_lines;

You missed the other early return from git_pipe. However, I think the approach is wrong; this is a great opportunity to use the dynamic scoping offered by 'local':

  else {
    local $/ = "\0";
    # do stuff with $/ as "\0"
  }
  # $/ has automatically been reset at the end of the block

Looking further at this bit of code, it seems even more confusing,
though. We split the output of rev-list on NUL, grab presumably the
entire thing (since there shouldn't be any NULs in the output, right?)
and then split it on newline into a list. Why aren't we doing this:
  else {
    open my $fd, ...;
    @commit_lines = map { chomp; $_ } <$fd>;
    ...

-Peff

Jakub Narebski· Sep 9, 2006, 22:00 UTC · re: Jeff King · lore

Re: [PATCH] gitweb: reset input record separator in parse_commit even on error

Jeff King wrote:

Show 26 quoted lines

> On Sat, Sep 09, 2006 at 05:12:36PM +0200, Sven Verdoolaege wrote:
> 
>> diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
>> index 7afdf33..60dd598 100755
>> --- a/gitweb/gitweb.perl
>> +++ b/gitweb/gitweb.perl
>> @@ -897,8 +897,8 @@ sub parse_commit {
>>              my $fd = git_pipe("rev-list", "--header", "--parents", "--max-count=1", $commit_id)
>>                      or return;
>>              @commit_lines = split '\n', <$fd>;
>> -            close $fd or return;
>>              $/ = "\n";
>> +            close $fd or return;
>>              pop @commit_lines;
>>      }
>>      my $header = shift @commit_lines;
> 
> You missed the other early return from git_pipe. However, I think the
> approach is wrong; this is a great opportunity to use the dynamic
> scoping offered by 'local':
> 
>   else {
>     local $/ = "\0";
>     # do stuff with $/ as "\0"
>   }
>   # $/ has automatically been reset at the end of the block

And this should be done consistently, for all plain formats 
(blob_plain, blobdiff_plain, commitdiff_plain), and some other
 places.

Sometimes it is
  local $/ = "\0";
more often
  local $/ = undef;
(or equivalently but slightly less human friendly, just 'local $/');

Show 8 quoted lines

> Looking further at this bit of code, it seems even more confusing,
> though. We split the output of rev-list on NUL, grab presumably the
> entire thing (since there shouldn't be any NULs in the output, right?)
> and then split it on newline into a list. Why aren't we doing this:
>   else {
>     open my $fd, ...;
>     @commit_lines = map { chomp; $_ } <$fd>;
>     ...

That is because by default git-rev-list separates output for different commits (when --header option is used) bu NULL... only because of "--max-count=1" there is only _one_ record... nevertheless it ends with "\0" (NULL) character.

-- 
Jakub Narebski
Warsaw, Poland
ShadeHawk on #git