Fix for ticket #146: Correctly handle reads of unused disk blocks at the

end of the file. (CVS 743)

FossilOrigin-Name: f5c2654768a6201fc554b59f1b2f56bcce738bc4

manifest

@@ -1,5 +1,5 @@
-C Always\sfill\sin\sthe\s5th\sparameter\sto\ssqlite_exec\sif\sthere\sis\san\serror.\s(CVS\s742)
+C Fix\sfor\sticket\s#146:\sCorrectly\shandle\sreads\sof\sunused\sdisk\sblocks\sat\sthe\nend\sof\sthe\sfile.\s(CVS\s743)
-D 2002-09-03T19:43:24
+D 2002-09-05T16:08:27
 F Makefile.in 420fada882179cb72ffd07313f3fd693f9f06640
 F Makefile.linux-gcc b86a99c493a5bfb402d1d9178dcdc4bd4b32f906
 F README f1de682fbbd94899d50aca13d387d1b3fd3be2dd
@@ -30,9 +30,9 @@ F src/hash.h cd0433998bc1a3759d244e1637fe5a3c13b53bf8
 F src/insert.c a2f5455009904476b43ec5304a181b505235f72f
 F src/main.c 367c0d2c72457dacddea28b5ba6634ffeaa9aa67
 F src/md5.c fe4f9c9c6f71dfc26af8da63e4d04489b1430565
-F src/os.c 00d10655e1dc9a52b4aabca58c8d8e45048057b0
+F src/os.c 091a89297bf80927cde146cd1dbf89c908864f3a
 F src/os.h 3009379b06941e7796a9812d1b6cbc59b26248c8
-F src/pager.c 4b0169e91b34f6ff91e8feb57545c43e4d6eb370
+F src/pager.c b5365348606252dee8d831912d916218df8f8720
 F src/pager.h 6991c9c2dc5e4c7f2df4d4ba47d1c6458f763a32
 F src/parse.y 818b03a73f6b3b8b284b515c5b1d9998d4663dc3
 F src/printf.c 5c50fc1da75c8f5bf432b1ad17d91d6653acd167
@@ -151,7 +151,7 @@ F www/speed.tcl a20a792738475b68756ea7a19321600f23d1d803
 F www/sqlite.tcl ae3dcfb077e53833b59d4fcc94d8a12c50a44098
 F www/tclsqlite.tcl 1db15abeb446aad0caf0b95b8b9579720e4ea331
 F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
-P dd8867fc479891ed8fa36c5cf2359e49c6754a8c
+P 7f8fd5c75d614f81ef87f0fc952c341cbc5076d0
-R cad73f796bba24cb230a5c691e09b6af
+R e7c2b185d8c4a6f19fc472c4852f3827
 U drh
-Z 60c2dd392b7d08c0b58d2cfa671b9836
+Z fa53bc156cff8bbf22e6de1d4e9ed324

manifest.uuid

@@ -1 +1 @@
-7f8fd5c75d614f81ef87f0fc952c341cbc5076d0
+f5c2654768a6201fc554b59f1b2f56bcce738bc4

src/os.c

@@ -479,8 +479,12 @@ int sqliteOsRead(OsFile *id, void *pBuf, int amt){
   SimulateIOError(SQLITE_IOERR);
   TRACE2("READ %d\n", last_page);
   got = read(id->fd, pBuf, amt);
-  if( got<0 ) got = 0;
+  /* if( got<0 ) got = 0; */
-  return got==amt ? SQLITE_OK : SQLITE_IOERR;
+  if( got==amt ){
+    return SQLITE_OK;
+  }else{
+    return SQLITE_IOERR;
+  }
 #endif
 #if OS_WIN
   DWORD got;
@@ -488,7 +492,11 @@ int sqliteOsRead(OsFile *id, void *pBuf, int amt){
   if( !ReadFile(id->h, pBuf, amt, &got, 0) ){
     got = 0;
   }
-  return got==amt ? SQLITE_OK : SQLITE_IOERR;
+  if( got==amt ){
+    return SQLITE_OK;
+  }else{
+    return SQLITE_IOERR;
+  }
 #endif
 }
 
@@ -498,17 +506,27 @@ int sqliteOsRead(OsFile *id, void *pBuf, int amt){
 */
 int sqliteOsWrite(OsFile *id, const void *pBuf, int amt){
 #if OS_UNIX
-  int wrote;
+  int wrote = 0;
   SimulateIOError(SQLITE_IOERR);
   TRACE2("WRITE %d\n", last_page);
-  wrote = write(id->fd, pBuf, amt);
+  while( amt>0 && (wrote = write(id->fd, pBuf, amt))>0 ){
-  if( wrote<amt ) return SQLITE_FULL;
+    amt -= wrote;
+    pBuf = &((char*)pBuf)[wrote];
+  }
+  if( amt>0 ){
+    return SQLITE_FULL;
+  }
   return SQLITE_OK;
 #endif
 #if OS_WIN
+  int rc;
   DWORD wrote;
   SimulateIOError(SQLITE_IOERR);
-  if( !WriteFile(id->h, pBuf, amt, &wrote, 0) || (int)wrote<amt ){
+  while( amt>0 && (rc = WriteFile(id->h, pBuf, amt, &wrote, 0))!=0 && wrote>0 ){
+    amt -= wrote;
+    pBuf = &((char*)pBuf)[wrote];
+  }
+  if( !rc || amt>(int)wrote ){
     return SQLITE_FULL;
   }
   return SQLITE_OK;
@@ -537,10 +555,18 @@ int sqliteOsSync(OsFile *id){
   SimulateIOError(SQLITE_IOERR);
   TRACE1("SYNC\n");
 #if OS_UNIX
-  return fsync(id->fd)==0 ? SQLITE_OK : SQLITE_IOERR;
+  if( fsync(id->fd) ){
+    return SQLITE_IOERR;
+  }else{
+    return SQLITE_OK;
+  }
 #endif
 #if OS_WIN
-  return FlushFileBuffers(id->h) ? SQLITE_OK : SQLITE_IOERR;
+  if( FlushFileBuffers(id->h) ){
+    return SQLITE_OK;
+  }else{
+    return SQLITE_IOERR;
+  }
 #endif
 }
 

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.51 2002/08/13 00:01:17 drh Exp $
+** @(#) $Id: pager.c,v 1.52 2002/09/05 16:08:27 drh Exp $
 */
 #include "sqliteInt.h"
 #include "pager.h"
@@ -1003,7 +1003,13 @@ int sqlitepager_get(Pager *pPager, Pgno pgno, void **ppPage){
       sqliteOsSeek(&pPager->fd, (pgno-1)*SQLITE_PAGE_SIZE);
       rc = sqliteOsRead(&pPager->fd, PGHDR_TO_DATA(pPg), SQLITE_PAGE_SIZE);
       if( rc!=SQLITE_OK ){
-        return rc;
+        int fileSize;
+        if( sqliteOsFileSize(&pPager->fd,&fileSize)!=SQLITE_OK
+               || fileSize>=pgno*SQLITE_PAGE_SIZE ){
+          return rc;
+        }else{
+          memset(PGHDR_TO_DATA(pPg), 0, SQLITE_PAGE_SIZE);
+        }
       }
     }
     if( pPager->nExtra>0 ){
@@ -1155,7 +1161,9 @@ int sqlitepager_begin(void *pData){
     }
     if( rc!=SQLITE_OK ){
       rc = pager_unwritelock(pPager);
-      if( rc==SQLITE_OK ) rc = SQLITE_FULL;
+      if( rc==SQLITE_OK ){
+        rc = SQLITE_FULL;
+      }
     }
   }
   return rc;
@@ -1363,7 +1371,9 @@ int sqlitepager_commit(Pager *pPager){
 
   if( pPager->errMask==PAGER_ERR_FULL ){
     rc = sqlitepager_rollback(pPager);
-    if( rc==SQLITE_OK ) rc = SQLITE_FULL;
+    if( rc==SQLITE_OK ){
+      rc = SQLITE_FULL;
+    }
     return rc;
   }
   if( pPager->errMask!=0 ){