diff --git a/manifest b/manifest
index e18705c664..a8574aaf05 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C New\stest-only\sSQL\sfunctions:\simplies_nonnull_row(),\sexpr_compare(),\sand\nexpr_implies_expr().\s\sThe\sSQLITE_TESTCTRL_INTERNAL_FUNCTIONS\stest-control\nis\smodified\sto\stoggle\sinternal\sfunction\saccess\son\sand\soff\sfor\sa\ssingle\ndatabase\sconnection.
-D 2020-01-01T15:43:30.603
+C Fix\sthe\ssqlite3ExprImpliesNonNullRow()\sroutine\sso\sthat\sit\scorrectly\nhandles\sa\snumeric\scomparison\sof\stwo\sAND\ssubexpressions.
+D 2020-01-01T16:43:41.805
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -480,7 +480,7 @@ F src/date.c e1d8ac7102f3f283e63e13867acb0efa33861cf34f0faf4cdbaf9fa7a1eb7041
 F src/dbpage.c 135eb3b5e74f9ef74bde5cec2571192c90c86984fa534c88bf4a055076fa19b7
 F src/dbstat.c 6c407e549406c10fde9ac3987f6d734459205239ad370369bc5fcd683084a4fa
 F src/delete.c a5c59b9c0251cf7682bc52af0d64f09b1aefc6781a63592c8f1136f7b73c66e4
-F src/expr.c 971e442fd52c493826a23e993de94e504adb10e5979d69169786af594687911b
+F src/expr.c e76660a57fa2bbe4103686dc8add1a8c5ca40ae139076956dc8c670f5af34e93
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 92a248ec0fa4ed8ab60c98d9b188ce173aaf218f32e7737ba77deb2a684f9847
 F src/func.c 259496e4856bd0a3215d16804992f3339f3e8db29f129a5a7285c341488bbe9c
@@ -855,7 +855,7 @@ F test/exclusive.test d6ccc6acc5d660544f8e0cacaec2c620f8ebb42a764d783ab53430e260
 F test/exclusive2.test 984090e8e9d1b331d2e8111daf6e5d61dda0bef7
 F test/exec.test e949714dc127eaa5ecc7d723efec1ec27118fdd7
 F test/exists.test 79a75323c78f02bbe9c251ea502a092f9ef63dac
-F test/expr.test 7cb55e80aeb41d65fec968c08212505123063fea60bdc355d764d747670e9eea
+F test/expr.test 26cd01e8485bc48c8aa6a1add598e9ce1e706b4eb4f3f554e0b0223022e8c2cf
 F test/expr2.test c27327ae9c017a7ff6280123f67aff496f912da74d78c888926d68b46ec75fd8
 F test/extension01.test 00d13cec817f331a687a243e0e5a2d87b0e358c9
 F test/extraquick.test cb254400bd42bfb777ff675356aabf3287978f79
@@ -1853,7 +1853,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 586a65a28fc6cac77309612abc32a2e1017c65e0387f9f438f5d8ac8406da8eb
-R 3b4f115c4445c4450469f73abe883b1d
+P 473892a8eceacf24d57fd0c72ff2a0b8be4e0d75e0af7a30bdb24fbc3b453601
+R 2d8f123f2e4a8a472445b72603dcb7b0
 U drh
-Z 13c9af33d91ecf550a075017a4801480
+Z d39001e583054b62fec0d63ed0de45b7
diff --git a/manifest.uuid b/manifest.uuid
index d2123d7daa..d44eaabffb 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-473892a8eceacf24d57fd0c72ff2a0b8be4e0d75e0af7a30bdb24fbc3b453601
\ No newline at end of file
+07e504d5174a1a8b1aa05ec5b44ac81ab3ea706c5a098caa88deb3d489cec8fb
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index da7e4bc349..1c03cf634e 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -5359,11 +5359,12 @@ static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
       return WRC_Prune;
 
     case TK_AND:
-      assert( pWalker->eCode==0 );
-      sqlite3WalkExpr(pWalker, pExpr->pLeft);
-      if( pWalker->eCode ){
-        pWalker->eCode = 0;
-        sqlite3WalkExpr(pWalker, pExpr->pRight);
+      if( pWalker->eCode==0 ){
+        sqlite3WalkExpr(pWalker, pExpr->pLeft);
+        if( pWalker->eCode ){
+          pWalker->eCode = 0;
+          sqlite3WalkExpr(pWalker, pExpr->pRight);
+        }
       }
       return WRC_Prune;
 
diff --git a/test/expr.test b/test/expr.test
index 3cdc9180e8..ec5c55c2e4 100644
--- a/test/expr.test
+++ b/test/expr.test
@@ -1036,4 +1036,24 @@ foreach {tn val} [list 1 NaN 2 -NaN 3 NaN0 4 -NaN0 5 Inf 6 -Inf] {
   } {0}
 }
 
+reset_db
+sqlite3_test_control SQLITE_TESTCTRL_INTERNAL_FUNCTIONS db
+do_execsql_test expr-16.1 {
+  CREATE TABLE t1(a,b,c);
+  CREATE TABLE dual(dummy);
+  INSERT INTO dual VALUES('X');
+} {}
+do_execsql_test expr-16.100 {
+  SELECT implies_nonnull_row( (b=1 AND 0)>(b=3 AND 0),a)
+  FROM dual LEFT JOIN t1;
+} {0}
+do_execsql_test expr-16.101 {
+  SELECT implies_nonnull_row( (b=1 AND 0)>(b=3 AND a=4),a)
+  FROM dual LEFT JOIN t1;
+} {1}
+do_execsql_test expr-16.102 {
+  SELECT implies_nonnull_row( (b=1 AND a=2)>(b=3 AND a=4),a)
+  FROM dual LEFT JOIN t1;
+} {1}
+
 finish_test