Dear Maintainer,
Commit 1f2bd775333f01cf3e2d521f2c817ad8ee0247d6 ("Convert ctags files from iso-8859-1 to utf-8") is incorrect and should be reverted. The relevant file is not in iso-8859-1; it is essentially an ASCII file that uses high octets as special separators. Converting breaks the file parsing.
In practice the effects of this can be seen by opening a file, typing the first few characters of e.g. "memcpy", and attempting to complete. Geany will suggest the nonsense string:
memcpyÌ1024Í(void * __dest, const void * __src, size_t __n)Ö0Ïvoid *
Similar failures can be seen with any other builtin C symbol.
I've tagged this with "patch", but the patch is just to revert the relevant commit.