Re: [PATCH] git-cvsserver: detect/diagnose write failure, etc.
From: Junio C Hamano <hidden>
Date: 2016-06-15 22:43:20
Jim Meyering [off-list ref] writes:
Beware: in some contexts (when running as server), one must not "die", but rather return an "error" indicator to the client. I did that in the second hunk. However, I haven't carefully audited the others, and so, some of the "die" calls I added may end up killing the server, when a gentler failure is required. I've just looked, and can confirm that my change to req_Modified (first hunk) is wrong. It should not die. Rather, it should probably do something like the "print "E ... in hunk#2. Ideally, someone would write a test to exercise code like this, to make sure it works. Jim
quoted hunk
diff --git a/git-cvsserver.perl b/git-cvsserver.perl index 5cbf27e..8d8d6f5 100755 --- a/git-cvsserver.perl +++ b/git-cvsserver.perl@@ -644,7 +644,7 @@ sub req_Modified $bytesleft -= $blocksize; } - close $fh; + close $fh or die "Failed to write temporary, $filename: $!";
True; dying is not appropriate here.
quoted hunk
@@ -901,8 +901,13 @@ sub req_update # projects (heads in this case) to checkout. # if ($state->{module} eq '') { + my $heads_dir = $state->{CVSROOT} . '/refs/heads'; + if (!opendir HEADS, $heads_dir) { + print "E [server aborted]: Failed to open directory, $heads_dir: $!\n" + . "error\n"; + return 0; + } print "E cvs update: Updating .\n"; - opendir HEADS, $state->{CVSROOT} . '/refs/heads'; while (my $head = readdir(HEADS)) { if (-f $state->{CVSROOT} . '/refs/heads/' . $head) { print "E cvs update: New directory `$head'\n";
Hmph. The clients get no entries in the listing either way, but I would say this is an improvement.
quoted hunk
@@ -1754,7 +1759,9 @@ sub req_annotate # git-jsannotate telling us about commits we are hiding # from the client. - open(ANNOTATEHINTS, ">$tmpdir/.annotate_hints") or die "Error opening > $tmpdir/.annotate_hints $!"; + my $a_hints = "$tmpdir/.annotate_hints"; + open(ANNOTATEHINTS, '>', $a_hints) + or die "Failed to open '$a_hints' for writing: $!"; for (my $i=0; $i < @$revisions; $i++) { print ANNOTATEHINTS $revisions->[$i][2];
Hmph, we seem to have:
$log->warn("Error in annotate output! LINE: $_");
print "E Annotate error \n";
which suggest me that throwing "E error" at the client and
returning might be better?
quoted hunk
@@ -1765,11 +1772,11 @@ sub req_annotate } print ANNOTATEHINTS "\n"; - close ANNOTATEHINTS; + close ANNOTATEHINTS or die "Failed to write $a_hints: $!"; - my $annotatecmd = 'git-annotate'; - open(ANNOTATE, "-|", $annotatecmd, '-l', '-S', "$tmpdir/.annotate_hints", $filename) - or die "Error invoking $annotatecmd -l -S $tmpdir/.annotate_hints $filename : $!"; + my @cmd = (qw(git-annotate -l -S), $a_hints, $filename); + open(ANNOTATE, "-|", @cmd) + or die "Error invoking ". join(' ',@cmd) .": $!"; my $metadata = {}; print "E Annotations for $filename\n"; print "E ***************\n";
Likewise...
quoted hunk
@@ -1996,12 +2003,12 @@ sub transmitfile { open NEWFILE, ">", $targetfile or die("Couldn't open '$targetfile' for writing : $!"); print NEWFILE $_ while ( <$fh> ); - close NEWFILE; + close NEWFILE or die("Failed to write '$targetfile': $!"); } else { print "$size\n"; print while ( <$fh> ); } - close $fh or die ("Couldn't close filehandle for transmitfile()"); + close $fh or die ("Couldn't close filehandle for transmitfile(): $!"); } else { die("Couldn't execute git-cat-file"); }
Ok.
quoted hunk
@@ -2501,17 +2508,14 @@ sub update if ($parent eq $lastpicked) { next; } - open my $p, 'git-merge-base '. $lastpicked . ' ' - . $parent . '|'; - my @output = (<$p>); - close $p; - my $base = join('', @output); + my $base = safe_pipe_capture('git-merge-base', + $lastpicked, $parent); chomp $base; if ($base) { my @merged; # print "want to log between $base $parent \n"; open(GITLOG, '-|', 'git-log', "$base..$parent") - or die "Cannot call git-log: $!"; + or die "Cannot call git-log: $!"; my $mergedhash; while (<GITLOG>) { chomp;
Ok.