Regression in console row scrolling (v2.6.2): first row sticky

[MoeMorox]

Bug Report

What's the issue you encountered?

Console scrolling no longer works correctly in libctru 2.6.2.

• The very first printed line becomes sticky in the first row of the console.
• Starting from the second line, scrolling happens normally, but the first line never scrolls off screen as it should.

No changes were made to devkitPro tooling besides updating to libctru 2.6.2-1 from pacman.

How can the issue be reproduced?

1. Initialize the console:

   gfxInitDefault();
   consoleInit(GFX_TOP, NULL);
   for (int i = 0; i < 100; i++) {
       printf("Line %d\n", i);
   }
   

2. Run the program until more lines than the screen can fit are printed.

3. Observe that the first line remains stuck at the top row.

Environment?

Host OS: WSL Ubuntu (6.6.87.2-microsoft-standard-WSL2)

libctru version: 2.6.2-1 (installed via pacman)

devkitARM: latest from pacman (unchanged)

Tested on:

Nintendo 3DS hardware

Azahar emulator

Additional context?

Screenshots / GIFs showing the issue:

bug_scroll_1.gif

bug_scroll_2.gif

Minimal repro program:

#include <3ds.h>
#include <stdio.h>

int main(int argc, char **argv)
{
    gfxInitDefault();
    consoleInit(GFX_TOP, NULL);

    int counter = 0;

    while (aptMainLoop())
    {
        hidScanInput();
        u32 kDown = hidKeysDown();

        if (kDown & KEY_START)
            break;

        printf("Zeile %d\n", counter++);

        gspWaitForVBlank();
        gfxSwapBuffers();
    }

    gfxExit();
    return 0;
}

v2.6.1: v.2.6.2: