diff --git a/manifest b/manifest
index 69e9a19f7f..22fa622242 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Merge\slatest\strunk\schanges\sinto\sthis\sbranch.
-D 2018-03-02T17:40:23.911
+C Update\sthis\sbranch\swith\srecent\scheckpoint\srelated\schanges\sfrom\strunk.
+D 2018-03-02T17:59:37.964
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in a2d2fb8d17c39ab5ec52beb27850b903949080848236923f436156b72a958737
@@ -572,7 +572,7 @@ F src/vdbesort.c 731a09e5cb9e96b70c394c1b7cf3860fbe84acca7682e178615eb941a3a0ef2
 F src/vdbetrace.c 48e11ebe040c6b41d146abed2602e3d00d621d7ebe4eb29b0a0f1617fd3c2f6c
 F src/vtab.c 0e4885495172e1bdf54b12cce23b395ac74ef5729031f15e1bc1e3e6b360ed1a
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
-F src/wal.c 44e8d9f9b42dba0dd6253d67574307ff1892ee56f3ae99cabfcec5a2676763b4
+F src/wal.c b6ad12df144846d02db4a18cadf9e5fcf39f1d7b7156f94131ab4076384dec07
 F src/wal.h 1713fefe4587678c295bbeb91c4e7442998ad74f19249869ce49dda9e8ce5d53
 F src/walker.c da987a20d40145c0a03c07d8fefcb2ed363becc7680d0500d9c79915591f5b1f
 F src/where.c 7cae47e813393d70c6d327fdf000fcb30f76b1b0b5a5b52ff6402e0c658de32c
@@ -1719,7 +1719,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 163c870950f386f6b0bb1ff9b3886cf95ba0deed414cae75baf87621ed3528c2 1293d4f64f322ee57510bdff497c54e0be2c9205217e1fd96887bba1f36bec40
-R d95135aa69ebdf39b1d9aaa7d36a2c84
+P 36801effa9ec67b551f58972e21794466420f10cd0420701fcd87695e6cd11ee 044b0b65e716bffeddedbd1b0360c4c332f6d2359167c1d327a5ff96539474cb
+R db5621b69ea924f8256c1ea108391b00
 U dan
-Z 069d19cd10e378f6784afc839a1c9bac
+Z 5f73e55771155cb4923ea7c8cff8af6b
diff --git a/manifest.uuid b/manifest.uuid
index 5638c6d4d4..fc240c969c 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-36801effa9ec67b551f58972e21794466420f10cd0420701fcd87695e6cd11ee
\ No newline at end of file
+fb6b7938601505186c0b1f0df6c45630039027f85ff394d290bc2c86b16a3a07
\ No newline at end of file
diff --git a/src/wal.c b/src/wal.c
index 75cb9bf665..6f2911ab38 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -1586,8 +1586,9 @@ static void walIteratorFree(WalIterator *p){
 
 /*
 ** Construct a WalInterator object that can be used to loop over all 
-** pages in the WAL in ascending order. The caller must hold the checkpoint
-** lock.
+** pages in the WAL following frame nBackfill in ascending order. Frames
+** nBackfill or earlier may be included - excluding them is an optimization
+** only. The caller must hold the checkpoint lock.
 **
 ** On success, make *pp point to the newly allocated WalInterator object
 ** return SQLITE_OK. Otherwise, return an error code. If this routine
@@ -1596,7 +1597,7 @@ static void walIteratorFree(WalIterator *p){
 ** The calling routine should invoke walIteratorFree() to destroy the
 ** WalIterator object when it has finished with it.
 */
-static int walIteratorInit(Wal *pWal, WalIterator **pp){
+static int walIteratorInit(Wal *pWal, u32 nBackfill, WalIterator **pp){
   WalIterator *p;                 /* Return value */
   int nSegment;                   /* Number of segments to merge */
   u32 iLast;                      /* Last frame in log */
@@ -1633,7 +1634,7 @@ static int walIteratorInit(Wal *pWal, WalIterator **pp){
     rc = SQLITE_NOMEM_BKPT;
   }
 
-  for(i=0; rc==SQLITE_OK && i<nSegment; i++){
+  for(i=walFramePage(nBackfill+1); rc==SQLITE_OK && i<nSegment; i++){
     volatile ht_slot *aHash;
     u32 iZero;
     volatile u32 *aPgno;
@@ -1789,13 +1790,6 @@ static int walCheckpoint(
   pInfo = walCkptInfo(pWal);
   if( pInfo->nBackfill<pWal->hdr.mxFrame ){
 
-    /* Allocate the iterator */
-    rc = walIteratorInit(pWal, &pIter);
-    if( rc!=SQLITE_OK ){
-      return rc;
-    }
-    assert( pIter );
-
     /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked
     ** in the SQLITE_CHECKPOINT_PASSIVE mode. */
     assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );
@@ -1832,7 +1826,13 @@ static int walCheckpoint(
       }
     }
 
-    if( pInfo->nBackfill<mxSafeFrame
+    /* Allocate the iterator */
+    if( pInfo->nBackfill<mxSafeFrame ){
+      rc = walIteratorInit(pWal, pInfo->nBackfill, &pIter);
+      assert( rc==SQLITE_OK || pIter==0 );
+    }
+
+    if( pIter
      && (rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(0),1))==SQLITE_OK
     ){
       i64 nSize;                    /* Current size of database file */