The way Text.draw is called by edit.draw, we know it'll never be called for lines above screen_top1.line. Comparing every line on screen with screen_top1 makes no sense. The intent is really just to compare with screen_top1 only for the first line, and otherwise to ignore this check.
XUGDTYW2OALZNGX52BJXFYW2IJ6YSXA62ANG2NX2KDWULYAPZYOAC
KURLAXXIKHKBL7UDFVIR26BI5FDO3ZFLIQASKVGJRDD3RETTOWNQC
Y4SPXCM3PKARGUU22FNBEDRU7S6CJSNYVAA76JYH4I4EMMMKP6LQC
H2DPLWMVRFYTO2CQTG54FMT2LF3B6UKLXH32CUA22DNQJVP5XBNQC
BULPIBEGL7TMK6CVIE7IS7WGAHGOSUJBGJSFQK542MOWGHP2ADQQC
ILOA5BYFTQKBSHLFMMZUVPQ2JXBFJD62ERQFBTDK2WSRXUN525VQC
HALS7E5UGKCP3DFY456F7Z3Y6WNGIABOCV2SHT34D5ZAGNCPV5PQC
X3F7ECSLGXCH6NBSDIH7LY47I4EG2RR5VFPEMM6ZVDYQIGFID4HQC