Crash using QgsComposerAttributeTableV2 after setting columns

[qgib]

Author Name: Loïc BARTOLETTI (@lbartoletti)
Original Redmine Issue: 17181
Affected QGIS version: 2.18.13
Redmine category:python_bindings_/_sipify

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QGis crash when you use this code into the console (with a real project):

@table = QgsComposerAttributeTableV2(iface.activeComposers()[0].composition(), False)
cols = table.columns()
newCol = QgsComposerTableColumn("test_for_crash")
newCol.setAttribute("$id")
cols.append(newCol)
table.setColumns(cols)
[i.heading() for i in table.columns()]@

Tested on Windows 7 QGis 2.18, Debian QGis 2.14 and FreeBSD 2.18.

Seems to be a bad_alloc. Here some logs from Debian:

Warning: QObject::connect: Cannot connect (null)::layerModified() to QgsComposerAttributeTableV2::refreshAttributes()
Segmentation fault

FreeBSD show a windows with this error:

cxxrt::bad_alloc

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Related issue(s): #25079 (relates)
Redmine related issue(s): 17180

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[qgib]

Author Name: Giovanni Manghi (@gioman)

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Is this related to #25079 ?

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• status_id was changed from Open to Feedback

[qgib]

Author Name: Loïc BARTOLETTI (@lbartoletti)

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No, they're different issues.
I'm working on several projects needing to use the composer and found these two bugs.

[qgib]

Author Name: Giovanni Manghi (@gioman)

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Loïc BARTOLETTI wrote:

No, they're different issues.
I'm working on several projects needing to use the composer and found these two bugs.

thanks, so please add a description to #25079 just not leave the link to stackexchange, thanks.

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• status_id was changed from Feedback to Open

[qgib]

Author Name: Jürgen Fischer (@jef-n)

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• relates was configured as Atlas crash using python #25079

[qgib]

Author Name: Denis Rouzaud (@3nids)

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• assigned_to_id removed Denis Rouzaud

[qgib]

Author Name: Nyall Dawson (@nyalldawson)

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Your code is a bit wrong:

cols = table.columns()
...
cols.append(newCol)
table.setColumns(cols)

table.columns() is returning a pointer to the table's columns, so any edits (such as appending columns) happens immediately. There's no need to call table.setColumns() after. This is causing the crash, because the table already has ownership of that columns object.

Admittedly, not the nicest api!

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• resolution was changed from to invalid
• status_id was changed from Open to Closed