libgphoto2-2.4.0 - PTPBUG_DELETE_SENDS_EVENT caused hang for Canon IXUS 55 and S3 IS

[Mark Kirkwood]

Recently I noticed that attempting to delete gphotos from my Canon IXUS 
55 in gtkam would just hang. After some experimentation, combined with 
looking at older sources (which did not hang), I tracked the behaviour 
down to the PTPBUG_DELETE_SENDS_EVENT flags in libgphoto2.

I purchased a Canon S3 IS for my parents, and briefly trialled this - 
noting the same behaviour.

In both cases removing the PTPBUG_DELETE_SENDS_EVENT flag in 
camlibs/ptp2/library.c appeared to fix the issue.

I've attached a patch for this.

I guess this might be worth a pr, but I wondered if other Canon owners 
were seeing this?

As the subject says, libgphoto2-2.4.0 is the version I'm patching.

Cheers

Mark