Index: src/delete.c
==================================================================
--- src/delete.c
+++ src/delete.c
@@ -796,12 +796,12 @@
   if( piPartIdxLabel ){
     if( pIdx->pPartIdxWhere ){
       *piPartIdxLabel = sqlite3VdbeMakeLabel(v);
       pParse->iPartIdxTab = iDataCur;
       sqlite3ExprCachePush(pParse);
-      sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
-                         SQLITE_JUMPIFNULL);
+      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
+                            SQLITE_JUMPIFNULL);
     }else{
       *piPartIdxLabel = 0;
     }
   }
   nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;

Index: src/expr.c
==================================================================
--- src/expr.c
+++ src/expr.c
@@ -3699,10 +3699,25 @@
     }
   }
   sqlite3ReleaseTempReg(pParse, regFree1);
   sqlite3ReleaseTempReg(pParse, regFree2);
 }
+
+/*
+** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
+** code generation, and that copy is deleted after code generation. This
+** ensures that the original pExpr is unchanged.
+*/
+void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){
+  sqlite3 *db = pParse->db;
+  Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);
+  if( db->mallocFailed==0 ){
+    sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);
+  }
+  sqlite3ExprDelete(db, pCopy);
+}
+
 
 /*
 ** Do a deep comparison of two expression trees.  Return 0 if the two
 ** expressions are completely identical.  Return 1 if they differ only
 ** by a COLLATE operator at the top level.  Return 2 if there are differences

Index: src/insert.c
==================================================================
--- src/insert.c
+++ src/insert.c
@@ -1379,12 +1379,12 @@
 
     /* Skip partial indices for which the WHERE clause is not true */
     if( pIdx->pPartIdxWhere ){
       sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
       pParse->ckBase = regNewData+1;
-      sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
-                         SQLITE_JUMPIFNULL);
+      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
+                            SQLITE_JUMPIFNULL);
       pParse->ckBase = 0;
     }
 
     /* Create a record for this index entry as it should appear after
     ** the insert or update.  Store that record in the aRegIdx[ix] register

Index: src/sqliteInt.h
==================================================================
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -3324,10 +3324,11 @@
 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, u8);
 #define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */
 #define SQLITE_ECEL_FACTOR   0x02  /* Factor out constant terms */
 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
+void sqlite3ExprIfFalseDup(Parse*, Expr*, int, int);
 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
 Table *sqlite3LocateTableItem(Parse*,int isView,struct SrcList_item *);
 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);

Index: test/index6.test
==================================================================
--- test/index6.test
+++ test/index6.test
@@ -324,7 +324,26 @@
 } {
   1 one value 1 
   2 two {} {} 
   3 three value 3
 }
+
+# 2015-06-11.  Assertion fault found by AFL
+#
+do_execsql_test index6-9.1 {
+  CREATE TABLE t9(a int, b int, c int);
+  CREATE INDEX t9ca ON t9(c,a) WHERE a in (10,12,20);
+  INSERT INTO t9 VALUES(1,1,9),(10,2,35),(11,15,82),(20,19,5),(NULL,7,3);
+  UPDATE t9 SET b=c WHERE a in (10,12,20);
+  SELECT a,b,c,'|' FROM t9 ORDER BY a;
+} {{} 7 3 | 1 1 9 | 10 35 35 | 11 15 82 | 20 5 5 |}
+do_execsql_test index6-9.2 {
+  DROP TABLE t9;
+  CREATE TABLE t9(a int, b int, c int, PRIMARY KEY(a)) WITHOUT ROWID;
+  CREATE INDEX t9ca ON t9(c,a) WHERE a in (10,12,20);
+  INSERT INTO t9 VALUES(1,1,9),(10,2,35),(11,15,82),(20,19,5);
+  UPDATE t9 SET b=c WHERE a in (10,12,20);
+  SELECT a,b,c,'|' FROM t9 ORDER BY a;
+} {1 1 9 | 10 35 35 | 11 15 82 | 20 5 5 |}
+
 
 finish_test