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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_UNCONFIRMED "
title="UNCONFIRMED - Redim Preserve for existing arrays is accepted without any index range, but acts differently as if the unchange index ranges are made explicit."
href="https://bugs.documentfoundation.org/show_bug.cgi?id=134712">134712</a>
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<th>Summary</th>
<td>Redim Preserve for existing arrays is accepted without any index range, but acts differently as if the unchange index ranges are made explicit.
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<th>Product</th>
<td>LibreOffice
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>All
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<th>OS</th>
<td>All
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<th>Status</th>
<td>UNCONFIRMED
</td>
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<th>Severity</th>
<td>normal
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<th>Priority</th>
<td>medium
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<th>Component</th>
<td>BASIC
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<th>Assignee</th>
<td>libreoffice-bugs@lists.freedesktop.org
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<th>Reporter</th>
<td>jag@psilosoph.de
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<p>
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<pre>To get the clue to the subject, go stepwise through the following code and
inspect the used array variables after each step:
Sub directRedim()
REM Should closely be related to <a class="bz_bug_link
bz_status_VERIFIED bz_closed"
title="VERIFIED FIXED - ReDim is slow when array custom type is explicitly known"
href="show_bug.cgi?id=129256">tdf#129256</a> .
Dim a(1 To 5, 1 To 3)
a(2, 2) = "§§"
b = a
Redim Preserve b
REM Should either be rejected (bad) or treated as if
REM the correct index ranges were explicitly given (good). See below!
a(2, 2) = "%%"
b(2, 2) = "Paragraphs"
a(2, 2) = "§§"
REM You see: You dont get it like with a dim c().
REM Basic applies the already set index ranges.
The functional identity of b with a persists.
Redim a(1 To 5, 1 To 3)
a(2, 2) = "§§"
b = a
Redim Preserve b(1 To 5, 1 To 3)
a(2, 2) = "%%"
b(2, 2) = "Paragraphs"
REM You see: b Now has an own identity disconnected from a
REM as if an assignment was following the the ByVal semantics.
REM Actually the treatment in both variants is different in an error-prone way.
End Sub
For conceptual reasons the second variant is the only useful one.
I'm not sure If there is much code relying on the first variant as is.
Assuming it's rarely used because factually doing nothing, a unification of the
behavior in the sense that the first variant would work like the second one
should be safe enough. It would clearly simplify and make more efficient the
creation of copies of arrays. Such an operation soetimes is actually needed.</pre>
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