unicode hyphen in man page instead of ASCII hyphen-minus

[mutageneral]

If you copy a flag from the man page, it won't work, as the man page is wrongly formatted and uses Unicode hyphens ‐ (U+2010) instead of the ASCII hyphen-minus - (U+002D).

Step to reproduce bug:

1. Open 2 terminals.
2. Run man scrot in one.
3. Type "scrot" in the other and wait before doing anything else.
4. Copy any options from the manpage to the other terminal. I do this very often. I will use ‐‐select in this example.
5. scrot will save the screenshot as "‐‐select" instead of running interactively as the "-" character is not the one on your keyboard but a Unicode one.

Aftermath:

ordici@chuwi-OpenSUSE:~/test
> scrot ‐‐select
ordici@chuwi-OpenSUSE:~/test
> ls
‐‐select

The man page itself does not have the Unicode character in it, but after comparing it to another man page, I saw that the other man page used the escape character "\" before each "-" and adding some to the scrot man page and opening it with man -l did fix the problem.

Therefore, here is a hacky way to fix the problem by adding a substitution command to create-man.sh:

sed -i 's/-/\\-/g' scrot.1

Now, this is not as good as it could be, as it also replace "-" that are non command related, as "scrot-1.10" from the bottom of the page, or

NAME
         scrot - command line screen capture utility

Other man page keep these as the Unicode hyphen, but it is still a lot better than what we got currently. Trying to figure out why my commands did not work took me a long time, when it was a frustrating indistinguishable imposter character.

[mutageneral]

Apparently, groff recently stopped fixing the issue of broken man pages and reverted to original AT&T behaviour and this is the reason why this bug is only now being recognized: https://lwn.net/Articles/947941/

[N-R-K]

The scrot manpage gets generated by txt2man. Manually adding \ in front of a hyphen in man/scrot.txt does not work correctly. The resulting manpage gets severely messed up:

Applying some sed post-processing in man/create-man.sh to turn each - into \- works:

 function create-man {
-txt2man -d "$T2M_DATE" -t $T2M_NAME -r $T2M_NAME-$T2M_VERSION -s $T2M_LEVEL -v "$T2M_DESC" $T2M_NAME.txt > $T2M_NAME.$T2M_LEVEL
+txt2man -d "$T2M_DATE" -t $T2M_NAME -r $T2M_NAME-$T2M_VERSION -s $T2M_LEVEL -v "$T2M_DESC" $T2M_NAME.txt | sed 's|-|\\-|g' > $T2M_NAME.$T2M_LEVEL
 }

This will of course turn every - into an ascii hyphen. But IMO that's fine. Unicode hyphen doesn't have any practical purpose in manpages anyways.

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What I'm wondering now is whether this change should be made on our end or if this is something that should be done in txt2man instead.

Ping: @eribertomota