Crash when clicking on magnifier spinbox

[qgib]

Author Name: Paolo Cavallini (@pcav)
Original Redmine Issue: 15566
Affected QGIS version: 2.16.3
Redmine category:unknown
Assignee: Sandro Santilli

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This happens when starting with --configpath, also on a clean dir.
Confirmed on 2.16.2 and 2.17, Debian. See https://lists.osgeo.org/pipermail/qgis-developer/2016-September/044628.html for details and gdb output.

[qgib]

Author Name: Denis Rouzaud (@3nids)

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Fatal: ASSERT failure in Job::startRender(): "pre-set DPI not equal to
painter's DPI (10 vs 9.6)", file
/tmp/buildd/qgis-2.17.0+git20160806+cb02b9f+13jessie/src/core

The DPI in QgsMapSettings is a double to allow small magnification scale
(i.e. zoom out) while QPaintDevice::logicalDpiX is an integer.

https://github.com/qgis/QGIS/blob/master/src/core/qgsmaprenderercustompainterjob.cpp#L73
This means that the application will crash if in Debug mode (not in
Release mode)

I am not sure if we can safely remove this.
Martin, may you have a look here?

[qgib]

Author Name: Richard Duivenvoorde (@rduivenvoorde)

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Just as input: when I do NOT use the --configpath option (so using the 'normal' settings from ~/.qgis2 and Qt stuff from ~/.config/QGIS
all is ok, and I can use the magnifier ok.

Looks like something is set in the 'normal' config, which apperently is not avaialbe in a fresh config?

[qgib]

Author Name: Nyall Dawson (@nyalldawson)

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• priority_id was changed from Normal to Severe/Regression

[qgib]

Author Name: Sandro Santilli (@strk)

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How about rounding to closest integer ?

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• assigned_to_id was configured as Sandro Santilli
• fixed_version_id was configured as Version 2.18

[qgib]

Author Name: Sandro Santilli (@strk)

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I could reproduce in final-2_16_3-97-gb779a6a and 2.17+ (f289ef3).
Could not reproduce in 2.14 branch, althought eh assertion is there too (maybe DPIMaxSetting was not a double back then?)

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• version was changed from 2.16.2 to 2.16.3

[qgib]

Author Name: Sandro Santilli (@strk)

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Fixed in changeset "acf74a6539a015dc5ae3e948c43163e01dde2d3d".

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• status_id was changed from Open to Closed

[qgib]

Author Name: Jürgen Fischer (@jef-n)

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• category_id was configured as Unknown