diff --git a/ext/fts2/fts2.c b/ext/fts2/fts2.c
index 65ad173abc..8273531ec6 100644
--- a/ext/fts2/fts2.c
+++ b/ext/fts2/fts2.c
@@ -1351,7 +1351,7 @@ static void docListUnion(
   DLWriter writer;
 
   if( nLeft==0 ){
-    dataBufferAppend(pOut, pRight, nRight);
+    if( nRight!=0) dataBufferAppend(pOut, pRight, nRight);
     return;
   }
   if( nRight==0 ){
@@ -1532,7 +1532,7 @@ static void docListOrMerge(
   DLWriter writer;
 
   if( nLeft==0 ){
-    dataBufferAppend(pOut, pRight, nRight);
+    if( nRight!=0 ) dataBufferAppend(pOut, pRight, nRight);
     return;
   }
   if( nRight==0 ){
diff --git a/ext/fts3/fts3.c b/ext/fts3/fts3.c
index 4aab1a0935..e2298b51f0 100644
--- a/ext/fts3/fts3.c
+++ b/ext/fts3/fts3.c
@@ -1335,7 +1335,7 @@ static void docListUnion(
   DLWriter writer;
 
   if( nLeft==0 ){
-    dataBufferAppend(pOut, pRight, nRight);
+    if( nRight!=0) dataBufferAppend(pOut, pRight, nRight);
     return;
   }
   if( nRight==0 ){
@@ -1633,7 +1633,7 @@ static void docListOrMerge(
   DLWriter writer;
 
   if( nLeft==0 ){
-    dataBufferAppend(pOut, pRight, nRight);
+    if( nRight!=0 ) dataBufferAppend(pOut, pRight, nRight);
     return;
   }
   if( nRight==0 ){
diff --git a/manifest b/manifest
index 1745e058be..5611dd668c 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Return\sSQLITE_MISUSE\sinstead\sof\scrashing\sif\sNULL\sis\s(incorrectly)\spassed\sto\ssqlite3_step().\sTicket\s#2773.\s(CVS\s4545)
-D 2007-11-15T16:04:15
+C Don't\sdo\sanything\swhen\sinput\sdoclists\sare\sboth\sempty.\s\sTicket\s#2774\s(CVS\s4546)
+D 2007-11-16T00:23:08
 F Makefile.arm-wince-mingw32ce-gcc ac5f7b2cef0cd850d6f755ba6ee4ab961b1fadf7
 F Makefile.in 30c7e3ba426ddb253b8ef037d1873425da6009a8
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -38,7 +38,7 @@ F ext/fts1/simple_tokenizer.c 1844d72f7194c3fd3d7e4173053911bf0661b70d
 F ext/fts1/tokenizer.h 0c53421b832366d20d720d21ea3e1f6e66a36ef9
 F ext/fts2/README.tokenizers 2ff290e0a130f6e7611f2e608cb3b5aaea721abc
 F ext/fts2/README.txt 8c18f41574404623b76917b9da66fcb0ab38328d
-F ext/fts2/fts2.c 02720dd6e35c1ec836d17de2c9941ee1c369d884
+F ext/fts2/fts2.c 9c7d635a3d48874c326d2376d900abf66a298d0f
 F ext/fts2/fts2.h da5f76c65163301d1068a971fd32f4119e3c95fa
 F ext/fts2/fts2_hash.c cafebb4620d19684c4c9872530012441df60f503
 F ext/fts2/fts2_hash.h e283308156018329f042816eb09334df714e105e
@@ -50,7 +50,7 @@ F ext/fts2/fts2_tokenizer1.c 8a545c232bdffafd117c4eeaf59789691909f26a
 F ext/fts2/mkfts2amal.tcl 974d5d438cb3f7c4a652639262f82418c1e4cff0
 F ext/fts3/README.tokenizers a97c9a55b3422f6cb04af9de9296fe2447ea4a78
 F ext/fts3/README.txt 8c18f41574404623b76917b9da66fcb0ab38328d
-F ext/fts3/fts3.c 80b5eb9081232712e204614734bc30a8dbbd2140
+F ext/fts3/fts3.c 2e77742df5822f14f835442e799e9d13cfb281d5
 F ext/fts3/fts3.h 3a10a0af180d502cecc50df77b1b22df142817fe
 F ext/fts3/fts3_hash.c 1c2dc969a5b485848fb804c0ac41a046f18a09c9
 F ext/fts3/fts3_hash.h 004b759e1602ff16dfa02fea3ca1c77336ad6798
@@ -282,7 +282,7 @@ F test/fts2c.test ffb5a35230ac72c4354535c547965ce6824537c0
 F test/fts2d.test b7eaa671ca9a16997f3e5b158ee777ae21052b0b
 F test/fts2e.test 2da13dbc2d009105f42196845c1e1ce136c03d38
 F test/fts2f.test cf84096235991709c1e61caa389632aa0a4f976d
-F test/fts2g.test 2638452a2ea809ae30e98acc3c063fe54c381d0a
+F test/fts2g.test d49d6f6c900e6e20a0fb980ec1cd568dee12af76
 F test/fts2h.test 223af921323b409d4b5b18ff4e51619541b174bb
 F test/fts2i.test 1b22451d1f13f7c509baec620dc3a4a754885dd6
 F test/fts2j.test f68d7611f76309bc8b94170f3740d9fbbc061d9b
@@ -298,7 +298,7 @@ F test/fts3ac.test 356280144a2c92aa7b11474afadfe62a437fcd69
 F test/fts3ad.test 32a114c6f214081f244f642bde9fd5517938788e
 F test/fts3ae.test 31d8137fc7c14b5b991e3c4fa041ad2ac1255c7b
 F test/fts3af.test d394978c534eabf22dd0837e718b913fd66b499c
-F test/fts3ag.test 107664eed6c42cf6886f2cdcd3afbf3950370b8b
+F test/fts3ag.test 1c316bedb40a7c962e38998df854ea3ae26a3daa
 F test/fts3ah.test ba181d6a3dee0c929f0d69df67cac9c47cda6bff
 F test/fts3ai.test d29cee6ed653e30de478066881cec8aa766531b2
 F test/fts3aj.test 584facbc9ac4381a7ec624bfde677340ffc2a5a4
@@ -587,7 +587,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P d05eb67dd6e171cfe8b9528aa3c7c953780d8c82
-R 9acff769b3adb7f693b9b5ea49173f93
-U danielk1977
-Z 8d55885cb813c4feb6a2a8686164b3b8
+P 3bfee76fa6191c6e3aaa4632949b53253c612f36
+R 71e33fb18b19046ee138d1704767511a
+U shess
+Z 2e4be0fc57c5fedb87f3cd5c96e1d006
diff --git a/manifest.uuid b/manifest.uuid
index 61f7adebf2..6aac4014a1 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3bfee76fa6191c6e3aaa4632949b53253c612f36
\ No newline at end of file
+75cb46f82a6a95dbe9e279dede299bafa2e91cae
\ No newline at end of file
diff --git a/test/fts2g.test b/test/fts2g.test
index e2caca27b6..4cffb91fc7 100644
--- a/test/fts2g.test
+++ b/test/fts2g.test
@@ -7,7 +7,7 @@
 # of this script is testing handling of edge cases for various doclist
 # merging functions in the FTS2 module query logic.
 #
-# $Id: fts2g.test,v 1.2 2007/04/19 18:36:32 shess Exp $
+# $Id: fts2g.test,v 1.3 2007/11/16 00:23:08 shess Exp $
 #
 
 set testdir [file dirname $argv0]
@@ -84,4 +84,10 @@ do_test fts2g-1.12 {
   execsql {SELECT rowid FROM t1 WHERE t1 MATCH 'also OR this'}
 } {1 2}
 
+# Empty left and right in docListOrMerge().  Each term matches neither
+# row, and when combined there was an assertion failure.
+do_test fts2g-1.13 {
+  execsql {SELECT rowid FROM t1 WHERE t1 MATCH 'something OR nothing'}
+} {}
+
 finish_test
diff --git a/test/fts3ag.test b/test/fts3ag.test
index 1e1171c412..f4f9c8f4e4 100644
--- a/test/fts3ag.test
+++ b/test/fts3ag.test
@@ -7,7 +7,7 @@
 # of this script is testing handling of edge cases for various doclist
 # merging functions in the FTS3 module query logic.
 #
-# $Id: fts3ag.test,v 1.1 2007/08/20 17:38:42 shess Exp $
+# $Id: fts3ag.test,v 1.2 2007/11/16 00:23:08 shess Exp $
 #
 
 set testdir [file dirname $argv0]
@@ -84,4 +84,10 @@ do_test fts3ag-1.12 {
   execsql {SELECT rowid FROM t1 WHERE t1 MATCH 'also OR this'}
 } {1 2}
 
+# Empty left and right in docListOrMerge().  Each term matches neither
+# row, and when combined there was an assertion failure.
+do_test fts3ag-1.13 {
+  execsql {SELECT rowid FROM t1 WHERE t1 MATCH 'something OR nothing'}
+} {}
+
 finish_test