First the shadow table mechanism so that it works even if the shadow table

comes before the virtual table in the sqlite_schema table, as can happen
after a VACUUM.

FossilOrigin-Name: 005a8642773556825fe4c5d0b2c12517d35289308a30df0151ef7f080acb0172

src/build.c

@@ -2492,6 +2492,40 @@ int sqlite3IsShadowTableOf(sqlite3 *db, Table *pTab, const char *zName){
 }
 #endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
 
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Table pTab is a virtual table.  If it the virtual table implementation
+** exists and has an xShadowName method, then loop over all other ordinary
+** tables within the same schema looking for shadow tables of pTab, and mark
+** any shadow tables seen using the TF_Shadow flag.
+*/
+void sqlite3MarkAllShadowTablesOf(sqlite3 *db, Table *pTab){
+  int nName;                    /* Length of pTab->zName */
+  Module *pMod;                 /* Module for the virtual table */
+  HashElem *k;                  /* For looping through the symbol table */
+
+  assert( IsVirtual(pTab) );
+  pMod = (Module*)sqlite3HashFind(&db->aModule, pTab->u.vtab.azArg[0]);
+  if( pMod==0 ) return;
+  if( NEVER(pMod->pModule==0) ) return;
+  if( pMod->pModule->xShadowName==0 ) return;
+  assert( pTab->zName!=0 );
+  nName = sqlite3Strlen30(pTab->zName);
+  for(k=sqliteHashFirst(&pTab->pSchema->tblHash); k; k=sqliteHashNext(k)){
+    Table *pOther = sqliteHashData(k);
+    assert( pOther->zName!=0 );
+    if( !IsOrdinaryTable(pOther) ) continue;
+    if( pOther->tabFlags & TF_Shadow ) continue;
+    if( sqlite3StrNICmp(pOther->zName, pTab->zName, nName)==0
+     && pOther->zName[nName]=='_'
+     && pMod->pModule->xShadowName(pOther->zName+nName+1)
+    ){
+      pOther->tabFlags |= TF_Shadow;
+    }
+  }
+}
+#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
+
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /*
 ** Return true if zName is a shadow table name in the current database
@@ -3006,13 +3040,12 @@ int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
   assert( pTable );
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  db->nSchemaLock++;
-  rc = sqlite3VtabCallConnect(pParse, pTable);
-  db->nSchemaLock--;
-  if( rc ){
-    return 1;
+  if( IsVirtual(pTable) ){
+    db->nSchemaLock++;
+    rc = sqlite3VtabCallConnect(pParse, pTable);
+    db->nSchemaLock--;
+    return rc;
   }
-  if( IsVirtual(pTable) ) return 0;
 #endif
 
 #ifndef SQLITE_OMIT_VIEW

src/sqliteInt.h

@@ -5050,9 +5050,11 @@ int sqlite3ReadOnlyShadowTables(sqlite3 *db);
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   int sqlite3ShadowTableName(sqlite3 *db, const char *zName);
   int sqlite3IsShadowTableOf(sqlite3*,Table*,const char*);
+  void sqlite3MarkAllShadowTablesOf(sqlite3*, Table*);
 #else
 # define sqlite3ShadowTableName(A,B) 0
 # define sqlite3IsShadowTableOf(A,B,C) 0
+# define sqlite3MarkAllShadowTablesOf(A,B)
 #endif
 int sqlite3VtabEponymousTableInit(Parse*,Module*);
 void sqlite3VtabEponymousTableClear(sqlite3*,Module*);

src/vtab.c

@@ -505,18 +505,14 @@ void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
     iReg = ++pParse->nMem;
     sqlite3VdbeLoadString(v, iReg, pTab->zName);
     sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg);
-  }
-
-  /* If we are rereading the sqlite_schema table create the in-memory
-  ** record of the table. The xConnect() method is not called until
-  ** the first time the virtual table is used in an SQL statement. This
-  ** allows a schema that contains virtual tables to be loaded before
-  ** the required virtual table implementations are registered.  */
-  else {
+  }else{
+    /* If we are rereading the sqlite_schema table create the in-memory
+    ** record of the table. */
     Table *pOld;
     Schema *pSchema = pTab->pSchema;
     const char *zName = pTab->zName;
-    assert( sqlite3SchemaMutexHeld(db, 0, pSchema) );
+    assert( zName!=0 );
+    sqlite3MarkAllShadowTablesOf(db, pTab);
     pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab);
     if( pOld ){
       sqlite3OomFault(db);