Fix an incorrect comment and possible integer overflow in pager

resulting from check-in [23ca23894af352ea].  Problem reported by
[forum:/forumpost/e2ea1a3f61|forum post e2ea1a3f61].  Also change
the datatype of Pager.pageSize to i64 even though page size never
exceeds 65536, in order to help prevent future problems of this kind.

FossilOrigin-Name: f4a552ed9f4ab35520b634954c39748cc7bda535f426280b79da1b99f70599ac

diff --git a/manifest b/manifest
index 8e2c3d6acc729383a7e407782638bdb7c6716379..4edb55e3dbe3148b6f6db474a99677c762ffb86c 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Make\sreplace.tcl\suseful\swith\sTCL\s8.4
-D 2021-09-10T22:00:43.203
+C Fix\san\sincorrect\scomment\sand\spossible\sinteger\soverflow\sin\spager\nresulting\sfrom\scheck-in\s[23ca23894af352ea].\s\sProblem\sreported\sby\n[forum:/forumpost/e2ea1a3f61|forum\spost\se2ea1a3f61].\s\sAlso\schange\nthe\sdatatype\sof\sPager.pageSize\sto\si64\seven\sthough\spage\ssize\snever\nexceeds\s65536,\sin\sorder\sto\shelp\sprevent\sfuture\sproblems\sof\sthis\skind.
+D 2021-09-13T13:53:13.560
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -531,7 +531,7 @@ F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
 F src/os_unix.c b11e4610769922253dec27d7af4a07ff84f65169d19bda5e9b12a152a706f7f5
 F src/os_win.c 77d39873836f1831a9b0b91894fec45ab0e9ca8e067dc8c549e1d1eca1566fe9
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
-F src/pager.c 95c255256b13827caf038c8f963d334784073f38ab6ef9d70371d9d04f3c43e0
+F src/pager.c 1d22bb9081167b2e27a64bf49c7a22ad70b50dedeb78cf22cfe8d8370afa0be5
 F src/pager.h 4bf9b3213a4b2bebbced5eaa8b219cf25d4a82f385d093cd64b7e93e5285f66f
 F src/parse.y 86aa016b281f61d7664dd8cb7808cab8114d14cfaf362a9b9fc9ead8f33546b7
 F src/pcache.c 084e638432c610f95aea72b8509f0845d2791293f39d1b82f0c0a7e089c3bb6b
@@ -1922,7 +1922,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P d577030cdad165474b082afbe64782e2eb3290331b0e3045b1e85ee6fe011504
-R e11d4d0cf2b693b49f8aa8017ef21f60
-U larrybr
-Z c88549a8ac5b53702887ce858b5cfbe8
+P 2dd61dd97b0326b59b0bc3c83b4d4b9acf811c5acae4d1003e7525ba7a26daf5
+R 66cc359b5bd82ddca4b6f4fbb9050fa7
+U drh
+Z 3e25a183a096e34ec8d9ba775c31b648

diff --git a/manifest.uuid b/manifest.uuid
index 47e65984cd3f582e2603abf6d0af80f94f04eb56..98e404b1e59f0b459c29cb8d8326d3e285cec9c3 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-2dd61dd97b0326b59b0bc3c83b4d4b9acf811c5acae4d1003e7525ba7a26daf5
\ No newline at end of file
+f4a552ed9f4ab35520b634954c39748cc7bda535f426280b79da1b99f70599ac
\ No newline at end of file

diff --git a/src/pager.c b/src/pager.c
index 12a78cde8023caf45375f034fce108378749ee83..a72ae73ea45c5c1927947200a721a7ba764823a8 100644 (file)
--- a/src/pager.c
+++ b/src/pager.c
@@ -679,8 +679,8 @@ struct Pager {
   i16 nReserve;               /* Number of unused bytes at end of each page */
   u32 vfsFlags;               /* Flags for sqlite3_vfs.xOpen() */
   u32 sectorSize;             /* Assumed sector size during rollback */
-  int pageSize;               /* Number of bytes in a page */
   Pgno mxPgno;                /* Maximum allowed size of the database */
+  i64 pageSize;               /* Number of bytes in a page */
   i64 journalSizeLimit;       /* Size limit for persistent journal files */
   char *zFilename;            /* Name of the database file */
   char *zJournal;             /* Name of the journal file */
@@ -6932,14 +6932,14 @@ int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint){
     }
     pPager->nSavepoint = nNew;
 
-    /* If this is a release of the outermost savepoint, truncate 
-    ** the sub-journal to zero bytes in size. */
+    /* Truncate the sub-journal so that it only includes the parts
+    ** that are still in use. */
     if( op==SAVEPOINT_RELEASE ){
       PagerSavepoint *pRel = &pPager->aSavepoint[nNew];
       if( pRel->bTruncateOnRelease && isOpen(pPager->sjfd) ){
         /* Only truncate if it is an in-memory sub-journal. */
         if( sqlite3JournalIsInMemory(pPager->sjfd) ){
-          i64 sz = (pPager->pageSize+4)*pRel->iSubRec;
+          i64 sz = (pPager->pageSize+4)*(i64)pRel->iSubRec;
           rc = sqlite3OsTruncate(pPager->sjfd, sz);
           assert( rc==SQLITE_OK );
         }