[sql] Import reference version of SQLite 3.8.7.4.

third_party/sqlite/sqlite-src-3080704/src/journal.c

 /*
 ** 2007 August 22
 **
 ** 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 41 matching lines @@
   int rc = SQLITE_OK;
   if( !p->pReal ){
     sqlite3_file *pReal = (sqlite3_file *)&p[1];
     rc = sqlite3OsOpen(p->pVfs, p->zJournal, pReal, p->flags, 0);
     if( rc==SQLITE_OK ){
       p->pReal = pReal;
       if( p->iSize>0 ){
         assert(p->iSize<=p->nBuf);
         rc = sqlite3OsWrite(p->pReal, p->zBuf, p->iSize, 0);
       }
+      if( rc!=SQLITE_OK ){
+        /* If an error occurred while writing to the file, close it before
+        ** returning. This way, SQLite uses the in-memory journal data to 
+        ** roll back changes made to the internal page-cache before this
+        ** function was called.  */
+        sqlite3OsClose(pReal);
+        p->pReal = 0;
+      }
     }
   }
   return rc;
 }
 
 /*
 ** Close the file.
 */
 static int jrnlClose(sqlite3_file *pJfd){
   JournalFile *p = (JournalFile *)pJfd;
@@ skipping 149 matching lines @@
 ** If the argument p points to a JournalFile structure, and the underlying
 ** file has not yet been created, create it now.
 */
 int sqlite3JournalCreate(sqlite3_file *p){
   if( p->pMethods!=&JournalFileMethods ){
     return SQLITE_OK;
   }
   return createFile((JournalFile *)p);
 }
 
+/*
+** The file-handle passed as the only argument is guaranteed to be an open
+** file. It may or may not be of class JournalFile. If the file is a
+** JournalFile, and the underlying file on disk has not yet been opened,
+** return 0. Otherwise, return 1.
+*/
+int sqlite3JournalExists(sqlite3_file *p){
+  return (p->pMethods!=&JournalFileMethods || ((JournalFile *)p)->pReal!=0);
+}
+
 /* 
 ** Return the number of bytes required to store a JournalFile that uses vfs
 ** pVfs to create the underlying on-disk files.
 */
 int sqlite3JournalSize(sqlite3_vfs *pVfs){
   return (pVfs->szOsFile+sizeof(JournalFile));
 }
 #endif