realloc fails on big screen sizes and / or with small fonts

[ManfredGahr]

steps to reproduce on 1920x1080 screen:

• untar st-0.9
• apply st-ligatures-20230105-0.9.diff
• edit config.h to resize font to pixelsize=10 or smaller
• compile (make)
• test (./st)
• maximize st window the realloc in line 95 of hb.c fails with hrunebuffer.capacity == 512

I was able to reproduce this on:

• Arch Linux x86_64 with gcc 13.1.1 and glibc 2.37-3
• Odroid xu4 Ubuntu 22.04.2 LTS armv7l with gcc 11.3.0 and glibc 2.35

[cog1to]

Seems fixed now, pushed to master. A very silly mistake on my part, thanks for catching.

[ManfredGahr]

Yes, works now (at least at my two machines...)