Editor segfaults when saving in Linux

[cesarmiquel]

When I try to save my work on Linux I get a segfault. I compiled the app with debug information and run with gdb to trace the error. The problem seems to be caused in src/loadave.c line 431:

#if defined(_WIN32)
    _wfopen_s(&fp, path, L"wt");
#else
    fp = fopen(path, "wt");
#endif

The problem is that fp is NULL. Upon inspecting the flags passed on to fopen() I noticed the t flag which I've never seen before. Upon looking at the documentation for fopen() I see no mention of that flag. I removed the flag (just left the standard w) and it seems to work fine. I'm submitting a patch to fix this and also check to make sure fp is non-null so that you don't loose everything if fopen() fails.

[cesarmiquel]

Hmmm... checking the Windows documentation it seems that the t flag exists and is called "text-mode translation flag". I searched a bit and I can't find anywhere saying it is available in Linux. On my computer fp returns NULL and the call to mxmlSaveFile(xml, fp, whitespaceCallback) with a NULL fp segaults.

References:

• https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/fopen-wfopen?view=msvc-170
• https://man7.org/linux/man-pages/man3/fopen.3.html

[cesarmiquel]

Hmm... strange. I'm not able to reproduce this. I did notice that if you try to write to a directory you don't have permissions to write to (like /) then fp will be NULL so I think this patch is harmless and makes sure rocket doesn't crash if you have permission issues. The t flag does nothing in Linux so I guess we can remove it. But it doesn't seem to crash Rocket. 🤔 why was fopen() returning NULL to me ...