spawn: don't append to scalarrefs on stdout/stderr

None of our current code relies on it, and I can't imagine it's
something we'd need in the future, actually...  This keeps the
door open for relying more on Spawn in TestCommon.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index 849438bc..9c680690 100644
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -401,7 +401,7 @@ sub read_out_err ($) {
                 seek($fh, 0, SEEK_SET);
                 my $dst = $opt->{$fd};
                 $dst = $opt->{$fd} = $dst->[1] if ref($dst) eq 'ARRAY';
-                PublicInbox::IO::read_all $fh, 0, $dst, length($$dst);
+                PublicInbox::IO::read_all $fh, 0, $dst
         }
 }