Bug report #13088

qgis-server mixing layer db-connections

Added by Tom Palan about 5 years ago. Updated about 5 years ago.

Category:QGIS Server
Affected QGIS version:master Regression?:No
Operating System:Linux / Ubuntu / Debian Easy fix?:No
Pull Request or Patch supplied:No Resolution:
Crashes QGIS or corrupts data:Yes Copied to github as #:21155



2 PostGIS databases
2 project files, one for each database

When using the qgis-web-client and qgis-server to display the projects, the qgis-server mixes the database-connections and displays data from the other project. This happens randomly, but is reproducible after a few tries.
It only happens when the 2 projects are accessed simultaneously (e.g. using 2 browsers, and switching between them).

I compiled qgis-server from source (2015-06-08), and added some debug statements. Somehow after the QgsPostgresProvider for the layer is created (Line: "p3: Table name is.."), some calls to featureSource return the right datasource-uri, and some use another.
That's how far I got.

This happens on my Ubuntu 14.04 /64bit and Debian Jessie 64bit, using Apache2

I would be happy to supply some more information.

example-debug-messages.txt Magnifier (3.55 KB) Tom Palan, 2015-07-08 04:26 AM

disable_layer_caching.patch Magnifier (581 Bytes) Tom Palan, 2015-07-09 06:08 AM


#1 Updated by Tom Palan about 5 years ago

Update: The problem only occures if the 2 projects have layers with the same name. Apparently somewhere in QgsWMSProjectParser::mapLayerFromStyle (when called with useCache=true) mixes layers from different projects.
I was able to "fix" it by disabling caching of layers, see patch. As this is only a temporary fix, could somebody with more knowledge of QGIS chime in?

#2 Updated by Marco Hugentobler about 5 years ago

  • Status changed from Open to Closed

It happened if two layers have the same id and the same layer name. But it should be fixed in master branch already (127dd64)

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