The reported bug is described in the joined TeXinfo document which also serve as a demonstration and test field to reproduce it.
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%!PS -- Bertrand Petit
/D{def}def/E{exch}D/G{get}D/I{2 div}D/U{dup}D/L{roll}D/Y{setgray}D/N{newpath}D
/O{N 0 0 moveto}D/P{pop}D/T{translate}D currentpagedevice/PageSize G U 0 G/w E
D 1 G /h E D w I h I T 0 Y 1 setlinewidth 0 1 2 { P 120 rotate 2 4 w U mul h U
mul add sqrt I 50 add {N 50 0 3 2 L 0 360 arc stroke}for}for/s{O true charpath
pathbbox exch 4 -1 L E sub I 3 1 L sub I} D /l(bp)D 0.94 Y /Helvetica findfont
22 scalefont setfont l s P(x)s exch P T O l show showpage
float-leading.texi
Description: TeXInfo document
