KRecentDocuments currently checks for duplicate entries, but its criteria are very restrictive: not only does the path need to match, but also the app that the path was opened with. As a result, if you open a file with two different apps (say, Kate and KWrite), you get two entries.
From a regular user perspective, these are duplicates--especially since the entries are not visibly badged in any way with what app they will open with, so they look identical. Even if they were, it's not really a useful feature; when you want to access a recently-used document, it's highly likely that you just want to use the default app to open it.
This patch removes the app-matching criteria and considers an entry a duplicate if only its path matches that of an existing entry.
BUG: 379129
FIXED-IN 5.50