Import wiredtiger: 4500a8ed93af91b15901d00a9f9c2587f94275f9 from branch mongodb-4.4

ref: f6ab94b43b..4500a8ed93
for: 4.4.0-rc0

WT-5616       Coverity: Memory leak
WT-5669       Prepare support with durable history: backport data format changes to 4.2
WT-5672       Prepare support with durable history: implement rollback_to_stable
WT-5674       Prepare support with durable history: add/debug functional tests
WT-5754       Ensure the value is globally visible before encode it into WT_ROW
WT-5813       Fix heap-use-after-free in __split_parent
WT-5855       Clean up operation tracking documentation
WT-5880       test/format backup missing expected log file
WT-5885       Improve WT rollback to stable verbose output for better debugging
WT-5887       Turn off verbose output when test/format output is redirected to a file
WT-5890       Bump log/WT version to facilitate upgrade/downgrade floor for MongoDB
WT-5894       Don't persist durable timestamp if it is same as commit timestamp
WT-5896       Recovery sometimes attempts rollback to stable with an absent history store file
WT-5898       Fix memory leak in verifying history store
WT-5899       Restore WT_PAGE_LAS_UPDATE on-disk page flag value to avoid break backward compatibility
WT-5900       Display failed version numbers in error message for version mismatch failures
WT-5910       Fix start_durable_ts when handling out-of-order updates

1 files changed, 4 insertions, 21 deletions

diff --git a/src/third_party/wiredtiger/test/format/backup.c b/src/third_party/wiredtiger/test/format/backup.c
index 46b6e7b879c..f0123418888 100644
--- a/src/third_party/wiredtiger/test/format/backup.c
+++ b/src/third_party/wiredtiger/test/format/backup.c
@@ -327,8 +327,8 @@ backup(void *arg)
     WT_CURSOR *backup_cursor;
     WT_DECL_RET;
     WT_SESSION *session;
-    uint32_t src_id, src_prev;
     u_int incremental, period;
+    uint32_t src_id;
     const char *config, *key;
     char cfg[512];
     bool full, incr_full;
@@ -382,28 +382,11 @@ backup(void *arg)
                 full = true;
                 incr_full = false;
             } else {
-                /*
-                 * 75% of the time, use the most recent source id. 25% of the time, use the id
-                 * that is from two incremental backups prior. The handling of the active files for
-                 * the source one or two incrementals prior is unpleasant but necessary.
-                 */
-                src_prev = mmrand(NULL, 1, 4) == 2 && g.backup_id >= 2 && full == false ? 2 : 1;
-                if (src_prev == 2) {
-                    /*
-                     * If we're going back two incrementals ago, set active_prev to the other list
-                     * of active files (i.e. the active list that is not the immediate previous
-                     * list) and overwrite active_prev with the current one.
-                     */
-                    active_now = active_prev;
-                    if (active_prev == &active[0])
-                        active_prev = &active[1];
-                    else
-                        active_prev = &active[0];
-                } else if (active_prev == &active[0])
+                if (active_prev == &active[0])
                     active_now = &active[1];
                 else
                     active_now = &active[0];
-                src_id = g.backup_id - src_prev;
+                src_id = g.backup_id - 1;
                 testutil_check(__wt_snprintf(cfg, sizeof(cfg),
                   "incremental=(enabled,src_id=ID%u,this_id=ID%" PRIu32 ")", src_id,
                   g.backup_id++));
@@ -476,7 +459,7 @@ backup(void *arg)
          * more incremental backups).
          */
         if (full)
-            incremental = g.c_logging_archive ? 1 : mmrand(NULL, 1, 5);
+            incremental = g.c_logging_archive ? 1 : mmrand(NULL, 1, 8);
         if (--incremental == 0) {
             check_copy();
             /* We ran recovery in the backup directory, so next time it must be a full backup. */