[QGIS-Developer] how compatible .qml files are ?

[Sandro Santilli]

On Sun, Sep 01, 2019 at 08:19:18AM +1000, Nyall Dawson wrote:
> On Sat, 31 Aug 2019 at 17:02, Sandro Santilli <strk at kbt.io> wrote:

> > Do you know which commit dropped the backward compatibility, exactly ?
> > Note that "something completely unused" (just re-reading your quoted
> > text) was actually still used by QGIS itself...
> 
> No, no idea sorry. It would have been 2-3 years ago now, and it was a
> mass deletion commit, so git blame won't be much use. You may be able
> to git blame qgsvectorlayer.cpp or qgsvectorlayerrenderer.cpp to find.

Could this be the one? 

  commit 8e5fb436b702b9ab3d2112557f57e5a49cdea03a
  Author: Martin Dobias <wonder.sk at gmail.com>
  Date:   Wed Dec 14 09:45:39 2016 +0800

      Remove QgsLabelingEngineInterface base class and implementation in QgsPalLabeling

      It was ready to go for some time, just waiting for QgsMapRender that still used it.

   src/core/qgsvectorlayerrenderer.cpp | 122
  +++++++++++++++++++++++++++++++++----------------------------------------------------------------------
   1 file changed, 39 insertions(+), 83 deletions(-)

Unfortunately `git log --grep compat` doesn't give many hints,
and the NEWS file doesn't have any section of broken backward
compatibility for the 3.0 section either.

--strk;