[groff] 21/31: [mm]: Validate `PS` macro calls better.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit e3335548f7b1bc13d48371bcd0641499e6f8ad56
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Sun Aug 14 22:08:48 2022 -0500

    [mm]: Validate `PS` macro calls better.
    
    * contrib/mm/m.tmac (PS): Validate better; check for 2 arguments
      exactly.
    
    Also recast diagnostic message to state expectations clearly instead of
    calling arguments "bad", which is vague.
---
 contrib/mm/ChangeLog | 4 ++++
 contrib/mm/m.tmac    | 6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/contrib/mm/ChangeLog b/contrib/mm/ChangeLog
index 5f23c39f5..1e58d80e9 100644
--- a/contrib/mm/ChangeLog
+++ b/contrib/mm/ChangeLog
@@ -1,3 +1,7 @@
+2022-08-14  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       * m.tmac (PS): Validate better; check for 2 arguments exactly.
+
 2022-08-14  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * m.tmac (PS): Refactor; drop dead code.  The `pic*in` register
diff --git a/contrib/mm/m.tmac b/contrib/mm/m.tmac
index a81d621fa..e642b9a3c 100644
--- a/contrib/mm/m.tmac
+++ b/contrib/mm/m.tmac
@@ -2397,7 +2397,11 @@ in=\\n[.i] fi=\\n[.u] .d=\\n[.d] nl=\\n[nl] pg=\\n[%]
 .de PS
 .br
 .SP .5
-.ie \\n[.$]<2 .@error "PS: bad arguments. Probably not processed with pic."
+.ie !\\n[.$]=2 \{\
+.      ds pic*msg PS: expected 2 arguments, got \\n[.$]\"
+.      as pic*msg ; not preprocessed with pic?\"
+.      @error \\*[pic*msg]
+.\}
 .el \{\
 .      if r ds*format .if !\\n[ds*lvl] .ne (u;\\$1)+1v
 .\}