Prevent the in-memory journal read cursor from entering an inconsistent state

when it reads the last few bytes out of the journal file.  Fix for
ticket [7f7f8026eda38].

FossilOrigin-Name: c232b99e65397725076b3b11311c46f5bcf51d33

diff --git a/manifest b/manifest
index d1f84240feccf5d51a9bbb4669d4068e11690394..cc7bc0dbb351ebd3164dcaaf16a125d050c88674 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sa\scouple\soptions\sto\sthe\sMSVC\smakefile.
-D 2016-04-06T17:32:23.768
+C Prevent\sthe\sin-memory\sjournal\sread\scursor\sfrom\sentering\san\sinconsistent\sstate\nwhen\sit\sreads\sthe\slast\sfew\sbytes\sout\sof\sthe\sjournal\sfile.\s\sFix\sfor\nticket\s[7f7f8026eda38].
+D 2016-04-07T21:22:16.307
 F Makefile.in f53429fb2f313c099283659d0df6f20f932c861f
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc b00bcf0ec7001857aea81ee39fae45d20f5f4e59
@@ -325,7 +325,7 @@ F src/mem1.c 6919bcf12f221868ea066eec27e579fed95ce98b
 F src/mem2.c f1940d9e91948dd6a908fbb9ce3835c36b5d83c3
 F src/mem3.c 8768ac94694f31ffaf8b4d0ea5dc08af7010a35a
 F src/mem5.c 9bf955937b07f8c32541c8a9991f33ce3173d944
-F src/memjournal.c 5253fd4335a8d9c64e5df25cb9da6329af5242c7
+F src/memjournal.c 2815ef7684671d93a1ec6a31e1e63c45de4b4d31
 F src/msvc.h d9ba56c6851227ab44b3f228a35f3f5772296495
 F src/mutex.c 8e45800ee78e0cd1f1f3fe8e398853307f4a085c
 F src/mutex.h 779d588e3b7756ec3ecf7d78cde1d84aba414f85
@@ -1459,10 +1459,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P e9bb4cf40f4971974a74468ef922bdee481c988b
-R df37ee2a76161156de26d87e281cecd3
-T *branch * branch-3.12.0
-T *sym-branch-3.12.0 *
-T -sym-trunk *
-U mistachkin
-Z 6c1198e706bb6e69068eb7abaf257f68
+P ea4de04d67aea5102fc640833cd0ec494990c109
+Q +c4b9c611bdcd85f31d68aaf114ee34a9f27eba6d
+R 5945c0680345e67d7d967acfb4c9368b
+U drh
+Z e67f9905999b6698f873c3efc43111f0

diff --git a/manifest.uuid b/manifest.uuid
index c9e5c2c232bba3bad3bc5e5e9e2a7e55f8979b68..8e9bce6600cea5640b9821e8392c24785268e0f6 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-ea4de04d67aea5102fc640833cd0ec494990c109
\ No newline at end of file
+c232b99e65397725076b3b11311c46f5bcf51d33
\ No newline at end of file

diff --git a/src/memjournal.c b/src/memjournal.c
index 4f0efc174ea01f6e6a524d203612f9068ae88619..fbfa7cb802436fb26c17f5d2552472cd166ba8dc 100644 (file)
--- a/src/memjournal.c
+++ b/src/memjournal.c
@@ -94,6 +94,7 @@ static int memjrnlRead(
 #endif
 
   assert( (iAmt+iOfst)<=p->endpoint.iOffset );
+  assert( p->readpoint.iOffset==0 || p->readpoint.pChunk!=0 );
   if( p->readpoint.iOffset!=iOfst || iOfst==0 ){
     sqlite3_int64 iOff = 0;
     for(pChunk=p->pFirst; 
@@ -104,6 +105,7 @@ static int memjrnlRead(
     }
   }else{
     pChunk = p->readpoint.pChunk;
+    assert( pChunk!=0 );
   }
 
   iChunkOffset = (int)(iOfst%p->nChunkSize);
@@ -115,7 +117,7 @@ static int memjrnlRead(
     nRead -= iSpace;
     iChunkOffset = 0;
   } while( nRead>=0 && (pChunk=pChunk->pNext)!=0 && nRead>0 );
-  p->readpoint.iOffset = iOfst+iAmt;
+  p->readpoint.iOffset = pChunk ? iOfst+iAmt : 0;
   p->readpoint.pChunk = pChunk;
 
   return SQLITE_OK;