PROCEDURE RESULTS IN GARBAGE BYTES

Issue:
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This problem occurs under the following conditions:

a) Stored procedure has a variable is declared as TEXT/BLOB.
b) Data is copied into the the variable using the
   SELECT...INTO syntax from a TEXT/BLOB column.

Data corruption can occur in such cases.

SOLUTION:
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The blob type does not allocate space for the string to be
stored. Instead it contains a pointer to the source string.
Since the source is deallocated immediately after the
select statement, this can cause data corruption.

As part of the fix for Bug #21143080, when the source was
part of the table's write-set, blob would allocate the
neccessary space. But this fix missed the possibility that,
as in the above case, the target might be a variable.

The fix will add the copy_blobs check that was removed by
the earlier fix.