Correctly handle attempts to add a UNIQUE or PRIMARY KEY column using

the ALTER TABLE statement.  Ticket #3651. (CVS 6291)

FossilOrigin-Name: dd179ff2986bc2a86d70bbe927fd0e123e17d398

2 files changed, 13 insertions, 8 deletions

diff --git a/src/alter.c b/src/alter.c
index f7c60266d..497415833 100644
--- a/src/alter.c
+++ b/src/alter.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that used to generate VDBE code
 ** that implements the ALTER TABLE command.
 **
-** $Id: alter.c,v 1.52 2009/01/20 16:53:40 danielk1977 Exp $
+** $Id: alter.c,v 1.53 2009/02/13 03:43:32 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -453,7 +453,7 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   assert( sqlite3BtreeHoldsAllMutexes(db) );
   iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
   zDb = db->aDb[iDb].zName;
-  zTab = pNew->zName;
+  zTab = &pNew->zName[16];  /* Skip the "sqlite_altertab_" prefix on the name */
   pCol = &pNew->aCol[pNew->nCol-1];
   pDflt = pCol->pDflt;
   pTab = sqlite3FindTable(db, zTab, zDb);
@@ -583,7 +583,11 @@ void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
 
   /* Put a copy of the Table struct in Parse.pNewTable for the
-  ** sqlite3AddColumn() function and friends to modify.
+  ** sqlite3AddColumn() function and friends to modify.  But modify
+  ** the name by adding an "sqlite_altertab_" prefix.  By adding this
+  ** prefix, we insure that the name will not collide with an existing
+  ** table because user table are not allowed to have the "sqlite_"
+  ** prefix on their name.
   */
   pNew = (Table*)sqlite3DbMallocZero(db, sizeof(Table));
   if( !pNew ) goto exit_begin_add_column;
@@ -595,7 +599,7 @@ void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
   nAlloc = (((pNew->nCol-1)/8)*8)+8;
   assert( nAlloc>=pNew->nCol && nAlloc%8==0 && nAlloc-pNew->nCol<8 );
   pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc);
-  pNew->zName = sqlite3DbStrDup(db, pTab->zName);
+  pNew->zName = sqlite3MPrintf(db, "sqlite_altertab_%s", pTab->zName);
   if( !pNew->aCol || !pNew->zName ){
     db->mallocFailed = 1;
     goto exit_begin_add_column;
diff --git a/src/build.c b/src/build.c
index c3cd21333..851071356 100644
--- a/src/build.c
+++ b/src/build.c
@@ -22,7 +22,7 @@
 **     COMMIT
 **     ROLLBACK
 **
-** $Id: build.c,v 1.517 2009/02/10 10:44:42 danielk1977 Exp $
+** $Id: build.c,v 1.518 2009/02/13 03:43:32 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -365,7 +365,7 @@ static void freeIndex(Index *p){
 ** it is not unlinked from the Table that it indexes.
 ** Unlinking from the Table must be done by the calling function.
 */
-static void sqliteDeleteIndex(Index *p){
+static void sqlite3DeleteIndex(Index *p){
   Index *pOld;
   const char *zName = p->zName;
 
@@ -525,7 +525,7 @@ void sqlite3DeleteTable(Table *pTable){
   for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
     pNext = pIndex->pNext;
     assert( pIndex->pSchema==pTable->pSchema );
-    sqliteDeleteIndex(pIndex);
+    sqlite3DeleteIndex(pIndex);
   }
 
 #ifndef SQLITE_OMIT_FOREIGN_KEY
@@ -2428,7 +2428,8 @@ void sqlite3CreateIndex(
   pDb = &db->aDb[iDb];
 
   if( pTab==0 || pParse->nErr ) goto exit_create_index;
-  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
+  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 
+       && memcmp(&pTab->zName[7],"altertab_",9)!=0 ){
     sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
     goto exit_create_index;
   }