Created attachment 147195 [details]
A test for diargam's autoTxRot.
The attached PPTX has a single diagram object per each of 3 slides, and on each page, the autoTxRot param  of <dgm:alg type="tx"> in ppt/diagrams/layoutN.xml is different. It is absent on the 1st slide (defaults to "upr" as per ); "none" on the 2nd slide; and "grav" on the 3rd slide.
Current master toward 6.3 does not properly orient the texts in the shapes, despite  claims to had implemented that in GSoC 2018.
 ECMA-376-1:2016 22.214.171.124 ST_AutoTextRotation (Auto Text Rotation)
Mike Kaganski committed a patch related to this issue.
It has been pushed to "master":
tdf#121844: properly implement autoTxRot support
It will be available in 6.3.0.
The patch should be included in the daily builds available at
https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.