postgres.git / summary / log / commit / refs

commit    e72f2115ef6d574c64f42ea8b4cbe96accee08b2
Author:   Robert Haas <rhaas@postgresql.org>
Date:     Thu Aug 06 17:25:45 2015 +0000

    Fix incorrect calculation in shm_mq_receive.
    
    If some, but not all, of the length word has already been read, and the
    next attempt to read sees exactly the number of bytes needed to complete
    the length word, or fewer, then we'll incorrectly read less than all of
    the available data.
    
    Antonin Houska


 src/backend/storage/ipc/shm_mq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/storage/ipc/shm_mq.c b/src/backend/storage/ipc/shm_mq.c
index d96627a774e..a49bd17feeb 100644
--- a/src/backend/storage/ipc/shm_mq.c
+++ b/src/backend/storage/ipc/shm_mq.c
@@ -488,7 +488,7 @@ shm_mq_receive(shm_mq_handle *mqh, Size *nbytesp, void **datap, bool nowait)
 			if (mqh->mqh_partial_bytes + rb > sizeof(Size))
 				lengthbytes = sizeof(Size) - mqh->mqh_partial_bytes;
 			else
-				lengthbytes = rb - mqh->mqh_partial_bytes;
+				lengthbytes = rb;
 			memcpy(&mqh->mqh_buffer[mqh->mqh_partial_bytes], rawdata,
 				   lengthbytes);
 			mqh->mqh_partial_bytes += lengthbytes;


[parent: 543e2057fb0e]