4 files changed, 20 insertions, 4 deletions
diff --git a/src/delete.c b/src/delete.c
index ef6aace1c..369cdaf6f 100644
--- a/src/delete.c
+++ b/src/delete.c
@@ -798,8 +798,8 @@ int sqlite3GenerateIndexKey(
       *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;
     }
diff --git a/src/expr.c b/src/expr.c
index 89eee29ec..06993e737 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -3703,6 +3703,21 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
 }
 
 /*
+** 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
diff --git a/src/insert.c b/src/insert.c
index 7e8741a9a..16bf07cdf 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -1381,8 +1381,8 @@ void sqlite3GenerateConstraintChecks(
     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;
     }
 
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 43e4b0be9..2378376c2 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3326,6 +3326,7 @@ int sqlite3ExprCodeExprList(Parse*, ExprList*, int, u8);
 #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 *);