Avoid returning MISUSE when sqlite is called recursively by an xBestIndex callback. (CVS 3274)

FossilOrigin-Name: 4339e1bf664c4287aabe0993a9c5a2b783019cb3

manifest

@@ -1,5 +1,5 @@
-C Add\stests\sto\sensure\striggers\scannot\sbe\screated\son\svirtual\stables.\s(CVS\s3273)
-D 2006-06-19T06:32:23
+C Avoid\sreturning\sMISUSE\swhen\ssqlite\sis\scalled\srecursively\sby\san\sxBestIndex\scallback.\s(CVS\s3274)
+D 2006-06-19T12:02:59
 F Makefile.in f839b470345d3cb4b0644068474623fe2464b5d3
 F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -84,7 +84,7 @@ F src/test4.c 8b784cd82de158a2317cb4ac4bc86f91ad315e25
 F src/test5.c 7162f8526affb771c4ed256826eee7bb9eca265f
 F src/test6.c 60a02961ceb7b3edc25f5dc5c1ac2556622a76de
 F src/test7.c 03fa8d787f6aebc6d1f72504d52f33013ad2c8e3
-F src/test8.c 9641e41a7d35588fc0a834439b6c404700e7c148
+F src/test8.c ac1def5e4f411a3ac24a58177cd771290054e4ce
 F src/test_async.c e3deaedd4d86a56391b81808fde9e44fbd92f1d3
 F src/test_loadext.c 22065d601a18878e5542191001f0eaa5d77c0ed8
 F src/test_md5.c 6c42bc0a3c0b54be34623ff77a0eec32b2fa96e3
@@ -105,7 +105,7 @@ F src/vdbeaux.c dc5cfd11a0529fcfd217a1807f7c9df513f1c276
 F src/vdbefifo.c 9efb94c8c3f4c979ebd0028219483f88e57584f5
 F src/vdbemem.c 5f0afe3b92bb2c037f8d5d697f7c151fa50783a3
 F src/vtab.c 8fbf4a8f718229d2158826ed6e440f2d32a07c80
-F src/where.c 0f1fcc2c7446b6dd947bf0069487b3ff282043ee
+F src/where.c 485d368d1f6c71713d6190cd730f9efde1385e6e
 F tclinstaller.tcl 046e3624671962dc50f0481d7c25b38ef803eb42
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/all.test 5df90d015ca63fcef2a4b62c24f7316b66c4bfd4
@@ -371,7 +371,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P d9b205acac34ba9703bc35dfb101aedd95cb5a16
-R b587e837f4d09c3b4bad373a725b9eeb
+P 9470e27962d2fe9c0d1921d9aab7d8f0047ac1fd
+R e911807803f92d410300bd3d3bd48573
 U danielk1977
-Z ba3c570300d0562a9cfe3fa18b037faa
+Z 123bfb4cc39e6acb4da9c11956198a0d

manifest.uuid

@@ -1 +1 @@
-9470e27962d2fe9c0d1921d9aab7d8f0047ac1fd
+4339e1bf664c4287aabe0993a9c5a2b783019cb3

src/test8.c

@@ -13,7 +13,7 @@
 ** is not included in the SQLite library.  It is used for automated
 ** testing of the SQLite library.
 **
-** $Id: test8.c,v 1.25 2006/06/17 09:39:56 danielk1977 Exp $
+** $Id: test8.c,v 1.26 2006/06/19 12:02:59 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "tcl.h"
@@ -427,6 +427,28 @@ static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   int nArg = 0;
   const char *zSep = "WHERE";
   echo_vtab *pVtab = (echo_vtab *)tab;
+  sqlite3_stmt *pStmt = 0;
+
+  int nRow;
+  int useIdx = 0;
+  int rc = SQLITE_OK;
+
+  /* Determine the number of rows in the table and store this value in local
+  ** variable nRow. The 'estimated-cost' of the scan will be the number of
+  ** rows in the table for a linear scan, or the log (base 2) of the 
+  ** number of rows if the proposed scan uses an index.  
+  */
+  zQuery = sqlite3_mprintf("SELECT count(*) FROM %Q", pVtab->zTableName);
+  rc = sqlite3_prepare(pVtab->db, zQuery, -1, &pStmt, 0);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+  sqlite3_step(pStmt);
+  nRow = sqlite3_column_int(pStmt, 0);
+  rc = sqlite3_finalize(pStmt);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
 
   zQuery = sqlite3_mprintf("SELECT rowid, * FROM %Q", pVtab->zTableName);
   for(ii=0; ii<pIdxInfo->nConstraint; ii++){
@@ -440,6 +462,7 @@ static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
     if( pVtab->aIndex[iCol] ){
       char *zCol = pVtab->aCol[iCol];
       char *zOp = 0;
+      useIdx = 1;
       if( iCol<0 ){
         zCol = "rowid";
       }
@@ -490,8 +513,17 @@ static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   pIdxInfo->idxNum = hashString(zQuery);
   pIdxInfo->idxStr = zQuery;
   pIdxInfo->needToFreeIdxStr = 1;
-  pIdxInfo->estimatedCost = 1.0;
-  return SQLITE_OK;
+  if( useIdx ){
+    /* Approximation of log2(nRow). */
+    for( ii=0; ii<(sizeof(int)*8); ii++ ){
+      if( nRow & (1<<ii) ){
+        pIdxInfo->estimatedCost = (double)ii;
+      }
+    }
+  } else {
+    pIdxInfo->estimatedCost = (double)nRow;
+  }
+  return rc;
 }
 
 static void string_concat(char **pzStr, char *zAppend, int doFree){

src/where.c

@@ -16,7 +16,7 @@
 ** so is applicable.  Because this module is responsible for selecting
 ** indices, you might also think of this module as the "query optimizer".
 **
-** $Id: where.c,v 1.219 2006/06/19 04:49:35 danielk1977 Exp $
+** $Id: where.c,v 1.220 2006/06/19 12:02:59 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 
@@ -983,6 +983,7 @@ static double bestVirtualIndex(
   WhereTerm *pTerm;
   int i, j;
   int nOrderBy;
+  int rc;
 
   /* If the sqlite3_index_info structure has not been previously
   ** allocated and initialized for this virtual table, then allocate
@@ -1122,7 +1123,14 @@ static double bestVirtualIndex(
   if( pIdxInfo->nOrderBy && !orderByUsable ){
     *(int*)&pIdxInfo->nOrderBy = 0;
   }
+
+  sqlite3SafetyOff(pParse->db);
   pTab->pVtab->pModule->xBestIndex(pTab->pVtab, pIdxInfo);
+  rc = sqlite3SafetyOn(pParse->db);
+  if( rc!=SQLITE_OK ){
+    sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));
+  }
+
   *(int*)&pIdxInfo->nOrderBy = nOrderBy;
   return pIdxInfo->estimatedCost;
 }