BIND 10 trac2850_3, updated. 6de9f8bf01a42ec823e9db70b42ffa301c4a928f [2850] Check the case where READ_WRITE mode doesn't find a checksum in an existing segment

[BIND 10 source code commits]

The branch, trac2850_3 has been updated
       via  6de9f8bf01a42ec823e9db70b42ffa301c4a928f (commit)
      from  465a926d11f043b79483f00bafb77b0926c1cb6b (commit)

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- Log -----------------------------------------------------------------
commit 6de9f8bf01a42ec823e9db70b42ffa301c4a928f
Author: Mukund Sivaraman <muks at isc.org>
Date:   Wed May 15 20:03:51 2013 +0530

    [2850] Check the case where READ_WRITE mode doesn't find a checksum in an existing segment
    
    Note that it's not possible to repeat a similar test for the
    ZoneTableHeader name as there are additional allocations by then.

-----------------------------------------------------------------------

Summary of changes:
 .../datasrc/memory/zone_table_segment_mapped.cc    |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

-----------------------------------------------------------------------
diff --git a/src/lib/datasrc/memory/zone_table_segment_mapped.cc b/src/lib/datasrc/memory/zone_table_segment_mapped.cc
index efadab7..d2830fc 100644
--- a/src/lib/datasrc/memory/zone_table_segment_mapped.cc
+++ b/src/lib/datasrc/memory/zone_table_segment_mapped.cc
@@ -80,6 +80,14 @@ ZoneTableSegmentMapped::processChecksum(MemorySegmentMapped& segment,
             }
         }
     } else {
+        if ((!create) && (!segment.allMemoryDeallocated())) {
+            // If we are resetting in READ_WRITE mode, and some memory
+            // was already allocated but there is no checksum, that
+            // indicates that the segment is corrupted.
+            error_msg = "Existing segment is missing a checksum name";
+            return (false);
+        }
+
         // Allocate space for a checksum (which is saved during close).
         void* checksum = NULL;
         while (!checksum) {
@@ -105,7 +113,7 @@ ZoneTableSegmentMapped::processHeader(MemorySegmentMapped& segment,
         segment.getNamedAddress(ZONE_TABLE_HEADER_NAME);
     if (result.first) {
         if (create) {
-            // There must be no previously saved checksum.
+            // There must be no previously saved header.
             error_msg = "There is already a saved ZoneTableHeader in the "
                  "segment opened in create mode";
             return (false);