Fix authorizer issue with fts3 in WebDatabase.

third_party/sqlite/src/ext/fts3/fts3.c

 /*
 ** 2006 Oct 10
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
@@ skipping 612 matching lines @@
   
     zSql = sqlite3_mprintf("PRAGMA %Q.page_size", p->zDb);
     if( !zSql ){
       rc = SQLITE_NOMEM;
     }else{
       rc = sqlite3_prepare(p->db, zSql, -1, &pStmt, 0);
       if( rc==SQLITE_OK ){
         sqlite3_step(pStmt);
         p->nPgsz = sqlite3_column_int(pStmt, 0);
         rc = sqlite3_finalize(pStmt);
+      }else if( rc==SQLITE_AUTH ){
+        p->nPgsz = 1024;

[michaeln, 2011/06/22 22:12:51]

1024... what if this hardcoded value does not match the actual page size in use?

Wow, this entire file has changed dramatically since the previous version, how
did the previous version figure out the page size?

Is there a more direct means of looking up the page size given an sqlite3 ptr?
Also an alternative may be to temporarily unhook the authorizer function while
performing this query and restoring it prior to return.

sqlite3* db;
db->xAuth = NULL;
db->pAuthArg = NULL;

[Scott Hess - ex-Googler, 2011/06/22 23:25:34]

AFAICT, the goal of pulling the page size is to improve the estimate for the
cost of pulling in certain data.  Having the wrong page size may cause a less
efficient code path, but it shouldn't be wildly less efficient, and correctness
should be preserved.

1024 is the default page size for SQLite.  I'll work on upstreaming the patch,
at which point I'm sure better suggestions will be made.  I also wanted to keep
the patch reasonable to merge to M-13.
This query optimization wasn't previously present.
I considered that, but it seemed a little dangerous to me - what if you got it
wrong and left the authorizer wide open, or allowed some sort of information
leakage?

+        rc= SQLITE_OK;

[Scott Hess - ex-Googler, 2011/06/22 23:25:34]

Oops, I'll get that whitespace.

       }
     }
     assert( p->nPgsz>0 || rc!=SQLITE_OK );
     sqlite3_free(zSql);
     *pRc = rc;
   }
 }
 
 /*
 ** "Special" FTS4 arguments are column specifications of the following form:
@@ skipping 3050 matching lines @@
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
 ){
   SQLITE_EXTENSION_INIT2(pApi)
   return sqlite3Fts3Init(db);
 }
 #endif
 
 #endif