[PATCH 7/7] git: avoid Perl5 internal scratchpad target cache

[Eric Wong <e@80x24.org>]

Creating a scalar ref directly off substr() seemed to be causing
the underlying non-ref scalar to end up in Perl's scratchpad.
Assign the substr result to a local variable seems sufficient to
prevent multi-megabyte SVs from lingering indefinitely when a
read-only daemon serves rare, oversized blobs.
---
 lib/PublicInbox/Git.pm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index e634ca55..9d2c5f75 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -158,7 +158,8 @@ sub my_read ($$$) {
 			return; # unrecoverable error
 		}
 	}
-	\substr($$rbuf, 0, $len, '');
+	my $no_pad = substr($$rbuf, 0, $len, '');
+	\$no_pad;
 }
 
 sub my_readline ($$) {