Ensure no continuations when block size equals super block size.

In this case each super block contains a single block so continuations are not possible.

doc/xml/release.xml

@@ -52,6 +52,7 @@
                         <commit subject="Exclude backup set size from info for block incremental backups."/>
                         <commit subject="Rename BlockHash to BlockChecksum."/>
                         <commit subject="Update default block size and super block values based on testing."/>
+                        <commit subject="Ensure no continuations when block size equals super block size."/>
 
                         <release-item-contributor-list>
                             <release-item-contributor id="david.steele"/>

src/command/backup/blockMap.c

@@ -137,6 +137,8 @@ blockMapNewRead(IoRead *const map, size_t checksumSize)
             // If the reference is continued use the prior offset and size values
             if (referenceEncoded & BLOCK_MAP_FLAG_CONTINUE)
             {
+                ASSERT(!blockEqual);
+
                 blockMapItem.offset = referenceData->offset;
                 blockMapItem.size = referenceData->size;
                 referenceContinue = true;
@@ -333,6 +335,8 @@ blockMapWrite(const BlockMap *const this, IoWrite *const output, const bool bloc
             // the last one for the reference.
             if (reference->offset == referenceData->offset)
             {
+                ASSERT(!blockEqual);
+
                 referenceEncoded |= BLOCK_MAP_FLAG_CONTINUE;
                 referenceContinue = true;
             }