Do not sum the checksum. Instead use the intermediary values in order to

correctly compute the final checksum. This is not a bug in the case where
both the sender and the receiver execute EXACTLY the same checksum
computations but is definitively a problem if not (such as the buffered case).

This commit was SVN r10367.

ompi/datatype/datatype_checksum.h

@@ -23,12 +23,12 @@
 
 #define MEMCPY_CSUM( DST, SRC, BLENGTH, CONVERTOR ) \
 do { \
-    (CONVERTOR)->checksum += OPAL_CSUM_BCOPY_PARTIAL( (SRC), (DST), (BLENGTH), (BLENGTH), &(CONVERTOR)->csum_ui1, &(CONVERTOR)->csum_ui2 ); \
+    (CONVERTOR)->checksum = OPAL_CSUM_BCOPY_PARTIAL( (SRC), (DST), (BLENGTH), (BLENGTH), &(CONVERTOR)->csum_ui1, &(CONVERTOR)->csum_ui2 ); \
 } while (0)
 
 #define COMPUTE_CSUM( SRC, BLENGTH, CONVERTOR ) \
 do { \
-    (CONVERTOR)->checksum += OPAL_CSUM_PARTIAL( (SRC), (BLENGTH), &(CONVERTOR)->csum_ui1, &(CONVERTOR)->csum_ui2 ); \
+    (CONVERTOR)->checksum = OPAL_CSUM_PARTIAL( (SRC), (BLENGTH), &(CONVERTOR)->csum_ui1, &(CONVERTOR)->csum_ui2 ); \
 } while (0)
 
 #else