open parenthesis in a section title changes formatting of getopts --man output

[adavies42]

i use a getopts construct which was suggested by Glenn Fowler on the old AT&T AST mailing list to generate indented, bold example lines followed by further-indented, normal-mode explanatory text; see https://www.mail-archive.com/ast-users@lists.research.att.com/msg00054.html for details

when i run the below script containing his example, in the tw -e "uid != 'bozo' || (mode & 'go=w')" line, the bold formatting ends at the || and the rest of the line, (mode & 'go=w')", is printed in normal mode

tested in homebrew 1.0.10 2024-08-01, but i've also checked as far back 93p (the earliest ksh93 i have access to), and the behavior there is identical

$ cat ./a.sh
#!/usr/bin/env ksh

USAGE+=$'[-?1.0.0][+NAME?foo - foo]'
USAGE+=$'[+DESCRIPTION?foo]'
USAGE+=$'[+EXAMPLES]'
USAGE+=$'    {'
USAGE+=$'        [+tw?Lists the current directory tree.]'
USAGE+=$'        [+tw chmod go-w?Turns off the group and other write permissions'
USAGE+=$'            for all files in the current directory tree using a minimal'
USAGE+=$'            amount of \bchmod\b(1) command execs.]'
USAGE+=$'        [+tw -e \"uid != \'bozo\' || (mode & \'go=w\')\"?Lists all'
USAGE+=$'            files in the current directory that don\'t belong to the user'
USAGE+=$'            \bbozo\b or have group or other write permission.]'
USAGE+=$'    }'
USAGE+=$'[-author?Aaron Davies]'
USAGE+=$'\n'
USAGE+=$'\n'

while getopts -a "${.sh.file##*/}" "$USAGE" OPTOPT
do
    :
done
$ ./a.sh --man
NAME
  foo - foo

SYNOPSIS
  foo [ options ]

DESCRIPTION
  foo

EXAMPLES
    tw    Lists the current directory tree.
    tw chmod go-w
          Turns off the group and other write permissions for all files in the current directory tree using a minimal amount of chmod(1) command execs.
    tw -e "uid != 'bozo' || (mode & 'go=w')"
          Lists all files in the current directory that don't belong to the user bozo or have group or other write permission.

IMPLEMENTATION
  version         1.0.0
  author          Aaron Davies
$ 

this doesn't happen with --nroff:

$ ./a.sh --nroff 2>&1|grep bozo
.H1 tw\ \-e\ "uid\ !=\ 'bozo'\ ||\ (mode\ &\ 'go=w')"
\fBbozo\fP or have group or other write permission\&.
$ 

[McDutchie]

Thanks for the report.

Looks like it's not actually the || that ends the bold formatting, but the subsequent (. If the opening parenthesis is deleted, the bold formatting is preserved.

[adavies42]

actually, i'm now wondering which is the intended behavior--given that this seems to be a reuse of the heading format, maybe it's deliberate that a heading would stop being bold after the first parenthesis. does anything in AST have a heading that includes parenthesis? i searched the current ksh93 codebase for /\[\+[^?]*\(/ and got a number of C hits that i don't know how to get to render, as it's not clear to me what their files actually build, but there are hits in one shell script which seem possibly relevant, in src/cmd/INIT/iffe.sh:

$ egrep '\[\+[^?]*\(' src/cmd/INIT/iffe.sh 
	[+define \aname\a [ (\aarg,...\a) ]] [ \avalue\a ]]?Emit a macro
	[+extern \aname\a \atype\a [ (\aarg,...\a) | [\adimension\a]] ]]?Emit
	[+(\aexpression\a)?Equivalent to \bexp -\b \aexpression\a.]
$ 

but when i run ksh src/cmd/INIT/iffe.sh --man and look for those lines, the formatting doesn't stop at the parenthesis

otoh, all the parenthesized text is inside other formatting instructions, so maybe those affect things somehow

btw, it looks like ksh is pretty aggressive about deciding to turn off formatting if it sees that stderr isn't a tty; i have to use script if i want to actually see the formatting codes

here's my sample script:

$ script -q /dev/null ./a.sh --man 2>&1|tr -d $'\r'|cat -vet
^[[1mNAME^[[0m$
  foo - foo$
$
^[[1mSYNOPSIS^[[0m$
  ^[[1mfoo^[[0m [ ^[[1;4moptions^[[0m ]$
$
^[[1mDESCRIPTION^[[0m$
  foo$
$
^[[1mEXAMPLES^[[0m$
    ^[[1mtw^[[0m    Lists the current directory tree.$
    ^[[1mtw chmod go-w^[[0m$
          Turns off the group and other write permissions for all files in the current directory tree using a minimal amount of ^[[1mchmod^[[0m(1) command execs.$
    ^[[1mtw -e "uid != 'bozo' || ^[[0m(mode & 'go=w')"$
          Lists all files in the current directory that don't belong to the user ^[[1mbozo^[[0m or have group or other write permission.$
$
^[[1mIMPLEMENTATION^[[0m$
  ^[[1mversion^[[0m         1.0.0$
  ^[[1mauthor^[[0m          Aaron Davies$
$ 

and here's iffe.sh, with just the relevant lines extracted:

$ script -q /dev/null ksh src/cmd/INIT/iffe.sh --man 2>&1|tr -d $'\r'|cat -vet|egrep -A 1 '^    \^\[\[1m(define|extern|\^\[\[0m\(\^\[\[1;4mexpression)'
    ^[[1mdefine ^[[0m^[[1;4mname^[[0m [ (^[[1;4marg,...^[[0m) ] [ ^[[1;4mvalue^[[0m ]$
          Emit a macro ^[[1m#define^[[0m for ^[[1;4mname^[[0m if it is not already defined. The definition is passed to subsequent tests.$
    ^[[1mextern ^[[0m^[[1;4mname^[[0m ^[[1;4mtype^[[0m [ (^[[1;4marg,...^[[0m) | [^[[1;4mdimension^[[0m] ]$
          Emit an ^[[1mextern^[[0m prototype for ^[[1;4mname^[[0m if one is not already defined. The prototype is passed to subsequent tests.$
--
    ^[[1m^[[0m(^[[1;4mexpression^[[0m)$
          Equivalent to ^[[1mexp -^[[0m ^[[1;4mexpression^[[0m.$
$ 

[McDutchie]

btw, it looks like ksh is pretty aggressive about deciding to turn off formatting if it sees that stderr isn't a tty; i have to use script if i want to actually see the formatting codes

You can also export ERROR_OPTIONS=emphasis to force it on.

[McDutchie]

I found the code that is responsible for the problem, and so far, I have been unable to find any downside to simply removing it. Nothing seems to break as far as I can tell.

diff --git a/src/lib/libast/misc/optget.c b/src/lib/libast/misc/optget.c
index acd106800..1a99f5d8a 100644
--- a/src/lib/libast/misc/optget.c
+++ b/src/lib/libast/misc/optget.c
@@ -1283,7 +1283,6 @@ label(Sfio_t* sp, int sep, char* s, int about, int z, int level, int style, int
 	Push_t*		tsp;
 
 	int		r = 0;
-	int		n = 1;
 	Push_t*		psp = 0;
 
 	if ((ostyle = style) > (STYLE_nroff - (sep <= 0)) && f != FONT_LITERAL && f >= 0)
@@ -1381,17 +1380,6 @@ label(Sfio_t* sp, int sep, char* s, int about, int z, int level, int style, int
 		}
 		switch (c = *s++)
 		{
-		case '(':
-			if (n)
-			{
-				n = 0;
-				if (f > 0)
-				{
-					sfputr(sp, font(f, style, 0), -1);
-					f = 0;
-				}
-			}
-			break;
 		case '?':
 		case ':':
 		case ']':