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  1. Qt
  2. QTBUG-79007

Memory leak when using boudingRect on QThread

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Not Evaluated
    • Resolution: Out of scope
    • Affects Version/s: 4.8.6
    • Fix Version/s: None
    • Component/s: GUI: Text handling
    • Labels:
      None
    • Platform/s:
      Linux/X11

      Description

      Hello,

      A memory leak is present when calling the boundingRect function in QFontMetrics (as well as drawText from QPainter) in a QThread.  In analyzing the source code for the two functions, I noticed they both made QStackTextEngine objects which are referenced in this bug report https://bugreports.qt.io/browse/QTBUG-24685 as causing a leak in version 4.7.4 and 4.8.  Supposedly the bug was fixed in 4.8.3 but it seems to be occuring in version 4.8.6 as well. I have attached images showing the memory increase when calling boundingRect with a QString of len == 0 (which returns the function before creating a QStackTextEngine and manipulating it) and one with  a QString of len != 0.  The first one has a RAM usage that is constant whereas the second has a RAM that increases steadily.

      In the images, the process concerned is called "Exemple"

      My question is, has this leak been corrected in a newer version or is it still a bug in Qt?

      Thank you in advance. 

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            • Assignee:
              esabraha Eskil Abrahamsen Blomfeldt
              Reporter:
              blcg B L
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