Hi, I can open a bug report for this, but this seems like a change someone familiar with the code could do in a few minutes, so I'm not sure it's worth the overhead.
The problem: Section 5.1.3 of groff info lists the input characters that by default are considered transparent when determining the end of a sentence: ", ', ), ], *, \[dg], \[rq] Missing from this list is \[cq]. Groff regards this as a distinct input character from ', even though ' and \[cq] usually (always?) output the same glyph. \[cq] is semantically the more correct way to indicate the closing single quote that should be ignored in end-of-sentence detection. The solution: In my superficial analysis, the code fix would seem to involve simply adding an additional "set_flags(charinfo::TRANSPARENT)" line with the other such lines in src/roff/troff/input.cpp. The documentation would have to be updated to match. The set of transparent characters is listed twice in doc/groff.texinfo (the regular expression dg.*rq is an easy way to find the two places). To me, the info file fix actually looks trickier than the code fix, as there are @cindex lines that would have to be added in addition to the change in the running text. The set is also listed in man/groff_diff.man. It may be documented other places that I am unaware of. It would be easy for me to create a patch with the above changes, but the fix would be better done by someone more familiar with the source code, who would better know if I am overlooking something or doing something wrong. (Or, perhaps, by someone looking to become more familiar with the source, who could do a more thorough analysis than I have.)
