Raylib: [textures] LoadImage(name) will crash if name does not contain a valid extension

[MikeDX]

Please, before submitting a new issue verify and check:

• [X] I tested it on latest raylib version from master branch
• [X] I checked there is no similar issue already reported
• [X] My code has no errors or misuse of raylib

Issue description

• When passing a filename to LoadImage, if the extension is omitted (for various reasons this could apply), Raylib will ultimately crash at TextToLower() with a null pointer.
  

  Code Example

Image myimage = LoadImage("myfile");

[hbiblia]

Hi

In version 2.5 I have this WARNING and I find no problem.

WARNING: Image file format [myfile] is not supported
WARNING: [myfile] Image could not be loaded

Hi

In version 2.5 I have this WARNING and I find no problem.

WARNING: Image file format [myfile] is not supported
WARNING: [myfile] Image could not be loaded

Just always check the null result.

[MikeDX]

Can you please try to replicate this with latest raylib version from master branch as I have done (and as is required by the issue submission process).

This could be my error (possible) but could also be a regression (possible).

It could also be a platform specific thing, but in my example, i do not even get a return from loadImage to check for a null result.

I will check again though 🙃

[MikeDX]

Having checked, it is raylib/core.c at fault, not me.

line 1835 of core.c :

bool result = false;
    const char *fileExt = GetExtension(fileName); // <-- GetExtension returns NULL here
    char fileExtLower[16] = { 0 };

    strcpy(fileExtLower, TextToLower(fileExt)); // TextToLower crashes here as explained in the issue report

fileExt is null at this point and is not being checked.

[raysan5]

@MikeDX Thanks! Issue reviewed in commit https://github.com/raysan5/raylib/commit/22b771328750a5baf138b0a125ecc21df1b1b49c.