Created attachment 5486 Use case in action. When trying to open a file with a custom command, the file selector for the desired executable doesn't escape the full path before setting the text widget's value, which in cases where the path contains spaces (for example) leads to a "Failed to execute application" error.
Created attachment 5487 Fix Based on Midnight Commander's strutils_shell_escape() function.
Alexander Schwinn referenced this bugreport in commit 441d99d9052fea46431a5df3ee9def5487b1069e Thunar's "open with" custom command doesn't escape the path (bug #10883) https://git.xfce.org/xfce/thunar/commit?id=441d99d9052fea46431a5df3ee9def5487b1069e
Sorry for the late reply and thanks for the patch! Sadly for thunar-master the patch did not work any more, since "thunar_util_str_shell_escape" was removed meanwhile. However like that I already knew what to do ;) Think I anyhow found a better way to fix this bug .. just take a look into the commit. Fix will be released within thunar 1.8.0
Wow, it's been a while. I barely recall having reported this - least of all having worked on a fix. But I'm glad it's been fixed. Thanks!
You are welcome .. better late than never :P