Change so that deleting an Expr structure requires only one frame per level in the expression tree, not two.

FossilOrigin-Name: a4380ab326e4b0de29271c824d041193e86b7139

5 files changed, 20 insertions, 34 deletions

diff --git a/manifest b/manifest
index a64490e71..0db8a02fe 100644
--- a/manifest
+++ b/manifest
@@ -1,8 +1,5 @@
------BEGIN PGP SIGNED MESSAGE-----
-Hash: SHA1
-
-C Bump\sthe\sversion\snumber\sto\s3.6.21.
-D 2009-11-23T13:17:27
+C Change\sso\sthat\sdeleting\san\sExpr\sstructure\srequires\sonly\sone\sframe\sper\slevel\sin\sthe\sexpression\stree,\snot\stwo.
+D 2009-11-23T14:39:15
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 7f6c6aa7feeeb5e26e01b344161d9aa1b5d64177
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -119,7 +116,7 @@ F src/callback.c 908f3e0172c3d4058f4ca0acd42c637c52e9669f
 F src/complete.c 417df1ef5ea798532bb6290b0cc4265fef82980a
 F src/date.c a79c0a8f219370b972e320741f995a3bef9df33f
 F src/delete.c ec04635d152debdab70d4b30c5516b59282075ea
-F src/expr.c bd248461bfb8290e3bb1da668660d42ab1a75464
+F src/expr.c 50385ed51f1cd7f1ab289629cd0f87d5b2fcca52
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c e2116672a6bd610dc888e27df292ebc7999c9bb0
 F src/func.c bf54e1202cbfb28bf4b1fd9b58899009ae76716f
@@ -163,13 +160,13 @@ F src/pragma.c 6936d7df5e04b9f996f8f320d15e65b6944b2caa
 F src/prepare.c ad90970bba3aead154266d8bb6faf9fbb5233b94
 F src/printf.c 03fabdd6112a0e23f78f8ac9a1396947ade0273b
 F src/random.c cd4a67b3953b88019f8cd4ccd81394a8ddfaba50
-F src/resolve.c aa3cb21e1ecd905c071fce8fb64d1a166cefc239
+F src/resolve.c c52d9e52e11058f4113f6644adc20d3f85141b1d
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c 2f9ed7482e7a25b0b127fc41693bbdbe1caf5647
 F src/shell.c f4948cb6d30665d755a6b5e0ec313d1094aab828
 F src/sqlite.h.in 4464e9772122f0447305d425e04d122b6f1bffec
 F src/sqlite3ext.h 69dfb8116af51b84a029cddb3b35062354270c89
-F src/sqliteInt.h e4d1e5233b2430b7e69ae551e16975304f5a60d6
+F src/sqliteInt.h 8ee7b66de2169dc958744e036b3b1550710a7b6e
 F src/sqliteLimit.h 3afab2291762b5d09ae20c18feb8e9fa935a60a6
 F src/status.c e651be6b30d397d86384c6867bc016e4913bcac7
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -775,14 +772,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P b6402b2065b844acb3f1bb94ad964568706bcb86
-R 4b616a70a19ad11911ec1cd1ff6b4d34
-U drh
-Z a06eed9e2c1f3955759bf18dccaf71fe
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-MrhYNgDkN4UdVQNYUggEijM=
-=D4Yq
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+P 39214aee6553db76309851e7aa74fcc02d4f59b7
+R 673f464af9f0a676a75a7dfadac3e11c
+U dan
+Z 0e8b7d6b7e381316eea3c397c4c24db2
diff --git a/manifest.uuid b/manifest.uuid
index 8aa5add71..44154a4bb 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-39214aee6553db76309851e7aa74fcc02d4f59b7
\ No newline at end of file
+a4380ab326e4b0de29271c824d041193e86b7139
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index 5254cd715..aee2b7409 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -627,11 +627,10 @@ void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
 }
 
 /*
-** Clear an expression structure without deleting the structure itself.
-** Substructure is deleted.
+** Recursively delete an expression tree.
 */
-void sqlite3ExprClear(sqlite3 *db, Expr *p){
-  assert( p!=0 );
+void sqlite3ExprDelete(sqlite3 *db, Expr *p){
+  if( p==0 ) return;
   if( !ExprHasAnyProperty(p, EP_TokenOnly) ){
     sqlite3ExprDelete(db, p->pLeft);
     sqlite3ExprDelete(db, p->pRight);
@@ -644,14 +643,6 @@ void sqlite3ExprClear(sqlite3 *db, Expr *p){
       sqlite3ExprListDelete(db, p->x.pList);
     }
   }
-}
-
-/*
-** Recursively delete an expression tree.
-*/
-void sqlite3ExprDelete(sqlite3 *db, Expr *p){
-  if( p==0 ) return;
-  sqlite3ExprClear(db, p);
   if( !ExprHasProperty(p, EP_Static) ){
     sqlite3DbFree(db, p);
   }
diff --git a/src/resolve.c b/src/resolve.c
index b763a809f..d913a24c8 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -87,7 +87,13 @@ static void resolveAlias(
     pDup->pColl = pExpr->pColl;
     pDup->flags |= EP_ExpCollate;
   }
-  sqlite3ExprClear(db, pExpr);
+
+  /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This 
+  ** prevents ExprDelete() from deleting the Expr structure itself,
+  ** allowing it to be repopulated by the memcpy() on the following line.
+  */
+  ExprSetProperty(pExpr, EP_Static);
+  sqlite3ExprDelete(db, pExpr);
   memcpy(pExpr, pDup, sizeof(*pExpr));
   sqlite3DbFree(db, pDup);
 }
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 293c2446b..a3980a071 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2544,7 +2544,6 @@ Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
-void sqlite3ExprClear(sqlite3*, Expr*);
 void sqlite3ExprDelete(sqlite3*, Expr*);
 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);