Created attachment 147695 [details] Sample document Open an OpenDocument presentation (.odp) that has a PNG image with alpha embedded in it. It won't show up. Interestingly, rotating the image just a bit makes it show up. Clearly the problem is somewhere in vcl, and it is iOS-specific. The sample document has two PNG images, one without alpha, one with. Only the first one shows up.
Confirmed. LOOLWSD master.. (git hash: b0b2c01a) LOKit Collabora Office 6.0-18 (git hash: 1913dcc)
As this is an iOS-specific problem, it is probably not useful to add it to that meta bug of cross-platform Impress bugs.
It is possible that the same root cause also prevents TIFF images in .pptx from showing up (once another bug in VCL has been fixed).
(At least the symptoms are the same, if one selects the image that is not displayed, and rotates a bit, it does show up.)
Tor Lillqvist committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/core/+/9c8478d428293c6223c8d1bdd1e93f7729b6d952%5E%21 tdf#122221: Bin apparently unnecessary early return It will be available in 6.4.0. 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: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Together with an earlier commit that was not marked with tdf#122221, the bug now seems fixed. (Both commits are also in the cp-6.0 branch.)
Tor Lillqvist committed a patch related to this issue. It has been pushed to "libreoffice-6-3": https://git.libreoffice.org/core/+/b0f9715174dc0001b2e738bd230f496432ab5ac6%5E%21 tdf#122221: Bin apparently unnecessary early return It will be available in 6.3.0.1. 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: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.