Bug report #14255

SVG preview blocks QGIS

Added by Paolo Cavallini over 10 years ago. Updated over 9 years ago.

Status:Closed
Priority:Severe/Regression
Assignee:Nyall Dawson
Category:Symbology
Affected QGIS version:master Regression?:No
Operating System:Debian Easy fix?:No
Pull Request or Patch supplied:No Resolution:
Crashes QGIS or corrupts data:No Copied to github as #:22251

Description

When changing a symbol to SVG, or in other instances where SVG preview should be created in vector properties, QGIS takes 100% of CPU, and the system lags for ages, even on a modern machine.

SVG_recursive_search_fails_with_circular_links.png - Dialog with the circular SVG path (147 KB) Jorge Rocha, 2016-07-04 01:24 AM

Associated revisions

Revision c60c4f7f
Added by Nyall Dawson over 9 years ago

Fix SVG preview blocks QGIS (fix #14255)

Now SVG preview loading occurs in a background thread so that
dialogs can open instantly

Revision 0b683637
Added by Nyall Dawson over 9 years ago

Merge pull request #3565 from nyalldawson/svg_background

Fix SVG preview blocks QGIS (fix #14255)

Revision ffafafdb
Added by Nyall Dawson over 9 years ago

Fix SVG preview blocks QGIS (fix #14255)

Now SVG preview loading occurs in a background thread so that
dialogs can open instantly

Also guard against circular symbolic links in SVG selector widget

(cherry-picked from c60c4f7f0ca09dc6bbc8e3f721339a238154ff57)

Revision bb2450ee
Added by Nyall Dawson over 9 years ago

Fix SVG preview blocks QGIS (fix #14255)

Now SVG preview loading occurs in a background thread so that
dialogs can open instantly

Also guard against circular symbolic links in SVG selector widget

(cherry-picked from c60c4f7f0ca09dc6bbc8e3f721339a238154ff57)

History

#1 Updated by Richard Duivenvoorde over 10 years ago

Hi Paolo,

can you provide more details to reproduce?

I'm here on Debian testing, but can perfectly fine load a point layer and select one of the svg symbols for it.

#2 Updated by Giovanni Manghi over 10 years ago

  • Status changed from Open to Feedback

No problems whatsoever on master on both Ubuntu and Windows. Please try another system and report back. Thanks.

#3 Updated by Paolo Cavallini over 10 years ago

Thanks for the feedback. In this case a packaging/dependency problem seems likely. Anyone on sid?

#4 Updated by Giovanni Manghi over 10 years ago

Paolo Cavallini wrote:

Thanks for the feedback. In this case a packaging/dependency problem seems likely. Anyone on sid?

If I'm not wrong Richard is on sid, and this would suggest a local issue.

#5 Updated by Paolo Cavallini over 10 years ago

Richard is on testing

#6 Updated by Giovanni Manghi over 10 years ago

Paolo Cavallini wrote:

Richard is on testing

have you tried other machines?

#7 Updated by Nyall Dawson about 10 years ago

Paolo- can I close this? No-one else is able to reproduce this issue.

#8 Updated by Paolo Cavallini about 10 years ago

  • Status changed from Feedback to Closed
  • Resolution set to worksforme

OK, thanks

#9 Updated by Jorge Rocha almost 10 years ago

Hi,

This same behavior is happening on 2.14.3 on Ubuntu.

After waiting several minutes for the dialog with the SVG symbols, with the CPU at 100%, I found out the following:
- QGIS is following symbolic links recursively to find SVG symbols to show on the dialog.

There are 3 SVG groups on the style dialog:
- jgr (my account)
- App Symbols
- User Symbols

The problem happens with symbols found in my account.

The path of a symbol, for example, is:
/home/jgr/WebstormProjects/MyDashBoard/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/public/server/node_modules/dns/public/css/fonts/glyphicons-halflings-regular.svg

In my case, in /home/jgr/WebstormProjects/MyDashBoard/server/public I have a symbolic link 'public' pointing to '..'.

I think we need to prevent that the search algorithm does not transverses that same link again.

#10 Updated by Jorge Rocha almost 10 years ago

Since the user can edit the SVG path (Settings → Options → System → SVG Path), if I remove the folder with circular links, the problem disappears.

#11 Updated by Andreas Neumann almost 10 years ago

Paolo: I wonder if your issue is the same? Can you please check if there are any circular symbolic links in your SVG paths?

I cannot replicate the issue on Ubuntu 16.04 and self compiled master. But I have no symbolic links in my SVG paths ...

#12 Updated by Andreas Neumann almost 10 years ago

  • Status changed from Reopened to Feedback

#13 Updated by Paolo Cavallini almost 10 years ago

No circular ref here.

#14 Updated by Giovanni Manghi almost 10 years ago

  • Status changed from Feedback to Open
  • Resolution deleted (worksforme)

#15 Updated by Andreas Neumann almost 10 years ago

Why is this bug still open? Apparently the issue with the accidental home folder is fixed in master and 2.16 and if a user is still affected (s)he can easily remove the home folder from the settings.

Not a big issue in my opinion and we should close this bug.

#16 Updated by Nyall Dawson almost 10 years ago

I still think this needs to be properly addressed, and make the svg preview run in a non blocking thread.

#17 Updated by Nyall Dawson over 9 years ago

  • Assignee set to Nyall Dawson

#18 Updated by Nyall Dawson over 9 years ago

PR at https://github.com/qgis/QGIS/pull/3565 - also fixes the circular symlink issue.

#19 Updated by Nyall Dawson over 9 years ago

  • Status changed from Open to Closed

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