Import wiredtiger: 2566118fc68b0124187e806bed52eb7cdbcb1be0 from branch mongodb-3.4

ref: 34182ad..2566118fc6
for: 3.3.12

WT-2631       nullptr is passed for parameters marked with attribute non-null
WT-2638       ftruncate may not be supported
WT-2645       wt dump: push the complexity of collecting metadata into a dump cursor
WT-2678       The metadata should not imply that an empty value is true
WT-2695       Integrate s390x accelerated crc32c support
WT-2719       add fuzz testing for WiredTiger options and reconfiguration.
WT-2734       Improve documentation of eviction behavior
WT-2766       Don't count eviction of lookaside file pages for the purpose of checking stuck cache
WT-2783       wtperf multi-btree.wtperf dumps core on Mac
WT-2787       Include src/include/wiredtiger_ext.h is problematic
WT-2795       Update documentation around read-only configuration
WT-2807       Switch Jenkins performance tests to tcmalloc
WT-2813       small cache usage stuck even with large cache
WT-2814       Enhance wtperf to support single-op truncate mode
WT-2816       Improve WiredTiger eviction performance
WT-2817       Investigate performance regression in develop, add workload to wtperf/runners
WT-2818       The page visibility check when queuing pages for eviction is overly restrictive
WT-2820       add gcc warn_unused_result attribute
WT-2822       panic mutex and other functions that cannot fail
WT-2823       support file handles without a truncate method
WT-2826       clang38 false positive on uninitialized variable.
WT-2827       checkpoint log_size configuration improvements
WT-2828       Make long wtperf tests reflect mongoDB usage
WT-2829       Switch automated testing to use enable-strict configure option
WT-2832       Python test uses hard-coded temporary directory
WT-2834       Join cursor: discrepancy with bloom filters
WT-2835       WT_CONNECTION.leak-memory can skip memory map and cache cleanup
WT-2838       Don't free session handles on close if leak memory is configured
WT-2839       lint: Ignoring return value of function
WT-2840       clang analysis: garbage values
WT-2841       Jenkins Valgrind runner is reporting errors in test wt2719_reconfig
WT-2843       Fix a bug in recovery if there is no filesystem truncate support
WT-2846       Several bugs related to reconfiguring eviction server at runtime
WT-2847       Merge fair locks into read/write locks.
WT-2850       clang 4.1 attribute warnings when building
WT-2853       Multi threaded reader writer example shows temporary slowdown or lockup
WT-2857       POSIX ftruncate calls should be #ifdef'd HAVE_FTRUNCATE
WT-2862       Fix lint error in test case for forced eviction with multiple cursors
WT-2863       Support UTF-8 paths on Windows

1 files changed, 2 insertions, 1 deletions

diff --git a/src/third_party/wiredtiger/src/include/buf.i b/src/third_party/wiredtiger/src/include/buf.i
index 95d945ec6d3..ebbee6b4633 100644
--- a/src/third_party/wiredtiger/src/include/buf.i
+++ b/src/third_party/wiredtiger/src/include/buf.i
@@ -76,7 +76,8 @@ __wt_buf_set(
 	WT_RET(__wt_buf_initsize(session, buf, size));
 
 	/* Copy the data, allowing for overlapping strings. */
-	memmove(buf->mem, data, size);
+	if (size != 0)
+		memmove(buf->mem, data, size);
 
 	return (0);
 }