use read_all in more places to improve safety

`readline' ops may not detect errors on partial reads.
This saves us some code to reduce cognitive overhead for
readers.  We'll also support reusing a destination buffers so it
can work more nicely with existing code.

1 files changed, 5 insertions, 4 deletions

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 35bd10ef..a460d155 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -550,11 +550,12 @@ sub modified ($;$) {
 
 # read_all/try_cat can probably be moved somewhere else...
 
-sub read_all ($;$) {
-        my ($fh, $len) = @_;
-        my $r = read($fh, my $buf, $len //= -s $fh);
+sub read_all ($;$$) {
+        my ($fh, $len, $bref) = @_;
+        $bref //= \(my $buf);
+        my $r = read($fh, $$bref, $len //= -s $fh);
         croak("$fh read ($r != $len)") if $len != $r;
-        $buf;
+        $$bref;
 }
 
 sub try_cat {