Fix text_unicode.c example crashing

[ghost]

The issue causing the examples/text/text_unicode.c to crash on PLATFORM_WEB was the Line Feed (LF) char \x0A on some entries of messages[] (L71, L77, L78, L79, L80, L81, L119, L120) not being escaped when being passed to SetClipboardText() (L195). All chars on those messages resolve to a singular unicode char, however, the Line Feed (LF) resolves to \n (with the \ plus n) which causes the unescaped error on web.

This can be solved by escaping the \x0A to \\n before passing it to SetClipboardText() if on PLATFORM_WEB (R195-R202).

@raysan5 Could you please check if that MemFree() call is correct? I saw the warning on the header about TextReplace() (L1417) but I'm not sure if I did that right.

Also (unrelated) small fix to float textOffsetY (R352).

Tested these proposed changes on Chromium (version 115.0.5790.170 64-bit) and Firefox (version 115.1.0esr 64-bit) both running on Linux (Linux Mint 21.1 64-bit).

Fixes #3249.

Edit 1: added line marks.
Edit 2: forgot to add the test environment.

[ghost]

Follow up issue

There appears to be some other problem on SetClipboardText() for web. Passing an unescaped char to it shouldn't cause the entire program/game to crash on web. Looking at its code (L2150) I expected it just not to finish, but not crashing.

I assembled a minimal reproduction code to test the issue:

#include "raylib.h"

int main(void) {
    InitWindow(800, 450, "test");
    SetTargetFPS(60);
    while (!WindowShouldClose()) {

        // Works
        if (IsKeyPressed(KEY_ONE))   SetClipboardText("1\\n2");

        // Crashes
        if (IsKeyPressed(KEY_TWO))   SetClipboardText("1\n2");

        BeginDrawing();
        ClearBackground(RAYWHITE);
        EndDrawing();
    }
    CloseWindow();
    return 0;
}

Note: Regardless, the text_unicode.c fix on the PR was still necessary because text_unicode.c should still pass a valid string to SetClipboardText() so it can complete successfully.

[raysan5]

@ubkp The issue is actually in SetClipboardText(), not properly supporting UTF-8 string data as it should, or at least not on PLATFORM_WEB. I think the easiest solution for this example is just removing that line and related code. It's not needed and I don't know why it is called.

SetClipboardText() on web could be threated as another separate issue.

[ghost]

@raysan5 Adjusted the fix as instructed (L190, L195).

I'll open a new issue about the SetClipboard().

[raysan5]

@ubkp thanks for the review!