Subject: [PATCH] Do not allow a virtual table to be renamed into the name of

 one of its shadows.

---

 src/alter.c     |  5 ++++-

 src/build.c     | 28 ++++++++++++++++++++++------

 src/sqliteInt.h |  5 +++++

 3 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/alter.c b/src/alter.c

index 1280e90..0fa24c0 100644

--- a/src/alter.c

+++ b/src/alter.c

@@ -117,7 +117,10 @@ void sqlite3AlterRenameTable(

   /* Check that a table or index named 'zName' does not already exist

   ** in database iDb. If so, this is an error.

   */

-  if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){

+  if( sqlite3FindTable(db, zName, zDb)

+   || sqlite3FindIndex(db, zName, zDb)

+   || sqlite3IsShadowTableOf(db, pTab, zName)

+  ){

     sqlite3ErrorMsg(pParse, 

         "there is already another table or index with this name: %s", zName);

     goto exit_rename_table;

diff --git a/src/build.c b/src/build.c

index e0fed8a..426428b 100644

--- a/src/build.c

+++ b/src/build.c

@@ -1899,6 +1899,27 @@ static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){

   recomputeColumnsNotIndexed(pPk);

 }

+

+#ifndef SQLITE_OMIT_VIRTUALTABLE

+/*

+** Return true if pTab is a virtual table and zName is a shadow table name

+** for that virtual table.

+*/

+int sqlite3IsShadowTableOf(sqlite3 *db, Table *pTab, const char *zName){

+  int nName;                    /* Length of zName */

+

+  if( !IsVirtual(pTab) ) return 0;

+  nName = sqlite3Strlen30(pTab->zName);

+  if( sqlite3_strnicmp(zName, pTab->zName, nName)!=0 ) return 0;

+  if( zName[nName]!='_' ) return 0;

+  Module *pMod = (Module*)sqlite3HashFind(&db->aModule, pTab->azModuleArg[0]);

+  if( pMod==0 ) return 0;

+  if( pMod->pModule->iVersion<3 ) return 0;

+  if( pMod->pModule->xShadowName==0 ) return 0;

+  return pMod->pModule->xShadowName(zName+nName+1);

+}

+#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

+

 #ifndef SQLITE_OMIT_VIRTUALTABLE

 /*

 ** Return true if zName is a shadow table name in the current database

@@ -1910,7 +1931,6 @@ static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){

 static int isShadowTableName(sqlite3 *db, char *zName){

   char *zTail;                  /* Pointer to the last "_" in zName */

   Table *pTab;                  /* Table that zName is a shadow of */

-  Module *pMod;                 /* Module for the virtual table */

   zTail = strrchr(zName, '_');

   if( zTail==0 ) return 0;

@@ -1919,11 +1939,7 @@ static int isShadowTableName(sqlite3 *db, char *zName){

   *zTail = '_';

   if( pTab==0 ) return 0;

   if( !IsVirtual(pTab) ) return 0;

-  pMod = (Module*)sqlite3HashFind(&db->aModule, pTab->azModuleArg[0]);

-  if( pMod==0 ) return 0;

-  if( pMod->pModule->iVersion<3 ) return 0;

-  if( pMod->pModule->xShadowName==0 ) return 0;

-  return pMod->pModule->xShadowName(zTail+1);

+  return sqlite3IsShadowTableOf(db, pTab, zName);

 }

 #else

 # define isShadowTableName(x,y) 0

diff --git a/src/sqliteInt.h b/src/sqliteInt.h

index b7d3571..76337f7 100644

--- a/src/sqliteInt.h

+++ b/src/sqliteInt.h

@@ -4407,6 +4407,11 @@ void sqlite3AutoLoadExtensions(sqlite3*);

    );

 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)

 #endif

+#ifndef SQLITE_OMIT_VIRTUALTABLE

+  int sqlite3IsShadowTableOf(sqlite3*,Table*,const char*);

+#else

+# define sqlite3IsShadowTableOf(A,B,C) 0

+#endif

 int sqlite3VtabEponymousTableInit(Parse*,Module*);

 void sqlite3VtabEponymousTableClear(sqlite3*,Module*);

 void sqlite3VtabMakeWritable(Parse*,Table*);

-- 

2.24.1