Program – Dereferencing Replaced Lines

When a line is replaced, references to dictionary entries in the old line must be removed.  This was taking place after the replacement line was encoded.  When a dictionary entry is dereferenced, the reference may no longer be used causing the dictionary entry to be made available for another entry.  The new line may add new dictionary entries, but with the encode before the dereferencing, the new entry will be added to the end of the dictionary if there are no free slots.

It is desirable for new dictionary entries to use slots that may be freed with the old line being replaced.  This will help the dictionary from growing larger then it needs to be.  Therefore, the dereference call was moved to before the encode call.  With this change, the results for encoder test #2 changed slightly, but only with respect to indexes of a couple of dictionary entries.

A previously undiscovered memory error was reported on encoder test #2 when running the memory test script.  The problem occurred in the constant string dictionary with the allocation of the string pointers for the QString instances.  While investigating this problem, another issue was discovered in the constant number dictionary, though this issue is much less serious and only results in wasted memory.  The conclusion was that the information dictionary class (currently defined as a template) needs to be redesigned.

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