[rt.cpan.org #61484] [patch] missing results with Win32::EventLog

Index: t/RT61484.t
===================================================================
--- t/RT61484.t	(revision 0)
+++ t/RT61484.t	(revision 0)
@@ -0,0 +1,98 @@
+use strict;
+use warnings;
+
+use Test::More tests => 122;
+
+
+{
+    package TestLogSeq;
+    use Win32::EventLog;
+
+    sub new
+    {
+        my $class = shift;
+        #$class = (ref $class) ? (ref $class) : $class;
+        my $log = Win32::EventLog->new('Application', '');
+        Test::More::isa_ok($log, 'Win32::EventLog', "$class log");
+        return bless {
+            log => $log,
+            flags => (EVENTLOG_SEQUENTIAL_READ | EVENTLOG_BACKWARDS_READ),
+        }, $class;
+    }
+
+    sub _next_offset
+    {
+        0
+    }
+
+    sub read
+    {
+        my $self = shift;
+        local $Win32::EventLog::GetMessageText = 1;
+        my ($flags, $offset) = ($self->{flags}, $self->_next_offset);
+        #printf "# %s: 0x%X %d\n", (ref $self), $flags, $offset;
+        $self->{log}->Read($flags, $offset, my $entry) or die "Read failure";
+        Test::More::is(ref $entry, 'HASH', "entry is HASHREF");
+        Test::More::ok(exists $entry->{RecordNumber}, "entry has RecordNumber");
+        if ($offset > 1) {
+            Test::More::is($entry->{RecordNumber}, $offset, "RecordNumber is $offset");
+        }
+        return $entry;
+    }
+
+    sub DESTROY
+    {
+        $_[0]->{log}->Close;
+    }
+}
+
+{
+    package TestLogSeek;
+    use Win32::EventLog;
+    use Test::More;
+
+    our @ISA = qw(TestLogSeq);
+
+    sub new
+    {
+        my $class = shift;
+        my $self = TestLogSeq::new($class, @_);
+        $self->{flags} = (EVENTLOG_SEEK_READ | EVENTLOG_BACKWARDS_READ);
+
+        my $log = $self->{log};
+
+        my ($oldest, $lastRec);
+        $log->GetOldest($oldest);
+        $log->GetNumber($lastRec);
+        $self->{offset} = $oldest + $lastRec;
+
+        return $self;
+    }
+
+    sub _next_offset
+    {
+        return --$_[0]->{offset};
+    }
+}
+
+
+sub check_entries
+{
+    my ($a, $b) = @_;
+    is(scalar localtime $a->{TimeGenerated}, scalar localtime $b->{TimeGenerated}, 'check TimeGenerated is "'.scalar(localtime $a->{TimeGenerated}).'"');
+    #foreach my $attr (qw(RecordNumber Computer Source EventType Category EventID Message)) {
+    foreach my $attr (qw(RecordNumber)) {
+        is($a->{$attr}, $b->{$attr}, "check $attr is $b->{$attr}");
+    }
+}
+
+
+my $log_seq = TestLogSeq->new;
+my $log_seek = TestLogSeek->new;
+
+foreach (1..15) {
+    pass "== Read $_ ==";
+    check_entries($log_seq->read, $log_seek->read);
+}
+
+# vim:set et sw=4 sts=4:
Index: Changes
===================================================================
--- Changes	(revision 502)
+++ Changes	(working copy)
@@ -1,5 +1,14 @@
 Revision history for Perl extension Win32::EventLog.
 
+0.077
+      - fix for skipped record when reading in SEQUENTIAL mode
+        (RT#61484) by Olivier Mengue
+      - the OFFSET argument is now completely ignored in SEQUENTIAL read
+        as in the underlying Win32 implementation. A '0' value previously
+        had a special behaviour which bypassed the cache and so gave
+        unpredictable results. Olivier Mengue.
+      - added test for RT#61484 by Olivier Mengue
+
 0.076 Wed Jul 02 2008 (Jan Dubois)
       - Make sure the regression tests are properly skipped on Win95
 
Index: EventLog.xs
===================================================================
--- EventLog.xs	(revision 502)
+++ EventLog.xs	(working copy)
@@ -26,9 +26,8 @@
     BOOL   wideEntries;			/* has unicode character entries */
     LPBYTE BufPtr;			/* pointer to data buffer */
     DWORD  BufLen;			/* size of buffer */
-    DWORD  NumEntries;			/* number of entries in buffer */
-    DWORD  CurEntryNum;			/* next entry to return */
     EVENTLOGRECORD *CurEntry;		/* point to next entry to return */
+    EVENTLOGRECORD *EndEntry;		/* point to after the last entry read */
     DWORD  Flags;			/* read flags for ReadEventLog */
 } EvtLogCtlBuf, *lpEvtLogCtlBuf;
 
@@ -278,12 +277,14 @@
     lpEvtLog = SVE(handle);
     if ((lpEvtLog != NULL) && (lpEvtLog->dwID == EVTLOGID)) {
 	DWORD NumRead, Required;
-	if (Flags != lpEvtLog->Flags) {
+	if (  (Flags != lpEvtLog->Flags)
+           || (lpEvtLog->CurEntry >= lpEvtLog->EndEntry)
+           || (((Flags & EVENTLOG_SEEK_READ) == EVENTLOG_SEEK_READ) && Record != lpEvtLog->CurEntry->RecordNumber)) {
 	    /* Reset to new read mode & force a re-read call */
 	    lpEvtLog->Flags      = Flags;
-	    lpEvtLog->NumEntries = 0;
+	    lpEvtLog->EndEntry = (EVENTLOGRECORD*) lpEvtLog->BufPtr;
 	}
-	if ((lpEvtLog->NumEntries == 0) || (Record != 0)) {
+	if (lpEvtLog->CurEntry >= lpEvtLog->EndEntry) {
 	redo_read:
             result = ReadEventLogA(lpEvtLog->hLog, Flags, Record,
                                    lpEvtLog->BufPtr, lpEvtLog->BufLen,
@@ -291,9 +292,9 @@
             lpEvtLog->wideEntries = FALSE;
 
 	    if (result)
-		lpEvtLog->NumEntries = NumRead;
+		lpEvtLog->EndEntry = (EVENTLOGRECORD*) (lpEvtLog->BufPtr + NumRead);
 	    else {
-		lpEvtLog->NumEntries = 0;
+		lpEvtLog->EndEntry = (EVENTLOGRECORD*) lpEvtLog->BufPtr;
 		if (Required > lpEvtLog->BufLen
 		    && GetLastError() == ERROR_INSUFFICIENT_BUFFER)
 		{
@@ -302,12 +303,12 @@
 		    goto redo_read;
 		}
 	    }
-	    lpEvtLog->CurEntryNum = 0;
-	    lpEvtLog->CurEntry    = (EVENTLOGRECORD*)lpEvtLog->BufPtr;
+	    lpEvtLog->CurEntry = (EVENTLOGRECORD*) lpEvtLog->BufPtr;
 	}
 
-	if (lpEvtLog->CurEntryNum < lpEvtLog->NumEntries) {
+	if (lpEvtLog->CurEntry < lpEvtLog->EndEntry) {
 	    EVENTLOGRECORD *LogBuf;
+	    /*printf("# CurEntryNum: %d   NumEntries: %d\n", lpEvtLog->CurEntryNum, lpEvtLog->NumEntries);*/
 	    LogBuf = lpEvtLog->CurEntry;
 	    SETPVN(3, (char*)LogBuf, LogBuf->Length);
 	    if (lpEvtLog->wideEntries) {
@@ -348,13 +349,7 @@
 		SETPVN(8, ((LPBYTE)LogBuf)+LogBuf->StringOffset, LogBuf->DataOffset-LogBuf->StringOffset);
 
 	    /* to next entry in buffer */
-	    lpEvtLog->CurEntryNum += LogBuf->Length;
 	    lpEvtLog->CurEntry = (EVENTLOGRECORD*)(((LPBYTE)LogBuf) + LogBuf->Length);
-	    if (lpEvtLog->CurEntryNum == lpEvtLog->NumEntries) {
-		lpEvtLog->NumEntries  = 0;
-		lpEvtLog->CurEntryNum = 0;
-		lpEvtLog->CurEntry    = NULL;
-	    }
 	    RETVAL = TRUE;
 	}
     }
@@ -684,9 +679,8 @@
     if (lpEvtLog->hLog) {
 	/* return info... */
 	lpEvtLog->dwID          = EVTLOGID;
-	lpEvtLog->NumEntries    = 0;
-	lpEvtLog->CurEntryNum   = 0;
-	lpEvtLog->CurEntry      = NULL;
+	lpEvtLog->CurEntry      = (EVENTLOGRECORD*) lpEvtLog->BufPtr;
+	lpEvtLog->EndEntry      = (EVENTLOGRECORD*) lpEvtLog->BufPtr;
 	lpEvtLog->Flags         = 0;
 	hEventLog = (size_t)lpEvtLog;
 	RETVAL = TRUE;
@@ -718,9 +712,8 @@
     if (lpEvtLog->hLog) {
 	/* return info... */
 	lpEvtLog->dwID          = EVTLOGID;
-	lpEvtLog->NumEntries    = 0;
-	lpEvtLog->CurEntryNum   = 0;
-	lpEvtLog->CurEntry      = NULL;
+	lpEvtLog->CurEntry      = (EVENTLOGRECORD*) lpEvtLog->BufPtr;
+	lpEvtLog->EndEntry      = (EVENTLOGRECORD*) lpEvtLog->BufPtr;
 	lpEvtLog->Flags         = 0;
 	hEventLog = (size_t)lpEvtLog;
 	RETVAL = TRUE;
Index: EventLog.pm
===================================================================
--- EventLog.pm	(revision 502)
+++ EventLog.pm	(working copy)
@@ -9,7 +9,7 @@
 
 use strict;
 use vars qw($VERSION $AUTOLOAD @ISA @EXPORT $GetMessageText);
-$VERSION = '0.076';
+$VERSION = '0.077';
 
 require Exporter;
 require DynaLoader;
@@ -276,6 +276,21 @@
 The Read() method read an EventLog entry from the EventLog represented
 by $handle.
 
+When using EVENTLOG_SEQUENTIAL_READ, OFFSET must have the following values:
+
+=over 4
+
+=item 1
+
+Reset read from start (either first or last record depending on
+EVENTLOG_FORWARDS_READ / EVENTLOG_BACKWARDS_READ flags)
+
+=item 0
+
+Read the next item.
+
+=back
+
 =item $handle->Close();
 
 The Close() method closes the EventLog represented by $handle. After
@@ -459,13 +474,15 @@
 
 =head1 BUGS
 
-None currently known.
+See L<https://rt.cpan.org/NoAuth/Bugs.html?Dist=Win32-EventLog>
 
 The test script for 'make test' should be re-written to use the
 EventLog object.
 
 =head1 AUTHOR
 
-Original code by Jesse Dougherty for HiP Communications. Additional
-fixes and updates attributed to Martin Pauley
-<[email protected]>) and Bret Giddings ([email protected]).
+Original code by Jesse Dougherty for HiP Communications.
+
+Additional fixes and updates attributed to Martin Pauley
+<[email protected]>), Bret Giddings (<[email protected]>)
+and Olivier MenguE<eacute> (<[email protected]>).