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authorJoshua Clayton <stillcompiling@gmail.com>2013-02-22 13:01:18 -0800
committerJunio C Hamano <gitster@pobox.com>2013-02-22 13:18:22 -0800
commit712c6adaeece262121c185a55e83a5074e2a8ea6 (patch)
tree0ba695c1bb79463406d2c1bd52e29e1061f54735
parent7e2010537e96d0a1144520222f20ba1dc3d61441 (diff)
downloadgit-712c6adaeece262121c185a55e83a5074e2a8ea6.tar.gz
git-712c6adaeece262121c185a55e83a5074e2a8ea6.tar.xz
Git.pm: fix cat_blob crashes on large files
Read and write each 1024 byte buffer, rather than trying to buffer the entire content of the file. We are only copying the contents to a file descriptor and do not use it ourselves. Previous code would crash on all files > 2 Gib, when the offset variable became negative (perhaps below the level of perl), resulting in a crash. On a 32 bit system, or a system with low memory it might crash before reaching 2 GiB due to memory exhaustion. This code may leave a partial file behind in case of failure, where the old code would leave a completely empty file. Neither version verifies the correctness of the content. Calling code must take care of verification and cleanup. Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r--perl/Git.pm17
1 files changed, 7 insertions, 10 deletions
diff --git a/perl/Git.pm b/perl/Git.pm
index 497f42017..cebf8f34c 100644
--- a/perl/Git.pm
+++ b/perl/Git.pm
@@ -890,20 +890,22 @@ sub cat_blob {
my $size = $1;
my $blob;
- my $bytesRead = 0;
+ my $bytesLeft = $size;
while (1) {
- my $bytesLeft = $size - $bytesRead;
last unless $bytesLeft;
my $bytesToRead = $bytesLeft < 1024 ? $bytesLeft : 1024;
- my $read = read($in, $blob, $bytesToRead, $bytesRead);
+ my $read = read($in, $blob, $bytesToRead);
unless (defined($read)) {
$self->_close_cat_blob();
throw Error::Simple("in pipe went bad");
}
-
- $bytesRead += $read;
+ unless (print $fh $blob) {
+ $self->_close_cat_blob();
+ throw Error::Simple("couldn't write to passed in filehandle");
+ }
+ $bytesLeft -= $read;
}
# Skip past the trailing newline.
@@ -918,11 +920,6 @@ sub cat_blob {
throw Error::Simple("didn't find newline after blob");
}
- unless (print $fh $blob) {
- $self->_close_cat_blob();
- throw Error::Simple("couldn't write to passed in filehandle");
- }
-
return $size;
}