[groff] 17/17: [man]: Add blank line and leading space traps.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 5e8ce0efba143265cbb0710b79d4319c88ddde3c
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Tue May 25 23:17:23 2021 +1000

    [man]: Add blank line and leading space traps.
    
    Add style warnings for man(7) documents with input lines that are blank
    or have leading spaces, since they can cause surprising rendering;
    enabled if the CHECKSTYLE register is greater than 2.
    
    * tmac/an-old.tmac (an-blank-line-trap, an-leading-space-trap): Issue
      style warning if enabled (and only if fill mode enabled in leading
      space trap); in any event, recreate the default *roff behavior.
    
      (TH): Install traps.
    
    * doc/andoc.tmac (reload-doc): Remove man(7) traps before loading
      doc.tmac.
---
 ChangeLog        | 16 ++++++++++++++++
 tmac/an-old.tmac | 17 +++++++++++++++++
 tmac/andoc.tmac  |  4 +++-
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 1d166d5..4ece993 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,21 @@
 2021-05-25  G. Branden Robinson <g.branden.robinson@gmail.com>
 
+       Add style warnings for man(7) documents with input lines that
+       are blank or have leading spaces, since they can cause
+       surprising rendering; enabled if the CHECKSTYLE register is
+       greater than 2.
+
+       * tmac/an-old.tmac (an-blank-line-trap, an-leading-space-trap):
+       Issue style warning if enabled (and only if fill mode enabled in
+       leading space trap); in any event, recreate the default *roff
+       behavior.
+       (TH): Install traps.
+
+       * doc/andoc.tmac (reload-doc): Remove man(7) traps before
+       loading doc.tmac.
+
+2021-05-25  G. Branden Robinson <g.branden.robinson@gmail.com>
+
        * doc/andoc.tmac (reload-doc): Fix spurious blank line.
 
 2021-05-25  G. Branden Robinson <g.branden.robinson@gmail.com>
diff --git a/tmac/an-old.tmac b/tmac/an-old.tmac
index 9cb4dd2..0eb568c 100644
--- a/tmac/an-old.tmac
+++ b/tmac/an-old.tmac
@@ -61,6 +61,20 @@
 .    an-style-warn use of deprecated macro: .\\$0
 ..
 .
+.de an-blank-line-trap
+.  if (\\n[CHECKSTYLE] > 2) \
+.    an-style-warn blank line in input
+.  sp
+..
+.
+.de an-leading-space-trap
+.  if (\\n[CHECKSTYLE] > 2) \
+.    if \\n[.u] \
+.      an-style-warn \\n[lsn] leading space(s) on input line
+.  br
+.  nop \h'\\n[lss]u'\c
+..
+.
 .\" Define alternate requests to handle continuous rendering.
 .\"
 .\" This .ne replacement avoids page breaks; instead, the page length is
@@ -143,6 +157,9 @@
 .  if ((\\n[.$] < 2) : (\\n[.$] > 5)) \
 .    an-style-warn .\\$0 expects 2 to 5 arguments, got \\n[.$]
 .
+.  blm an-blank-line-trap
+.  lsm an-leading-space-trap
+.
 .  \" If batch processing (rendering multiple) man page documents, we
 .  \" must handle the end of a previous document.
 .  if !\\n[an-is-first-page-of-document] \{\
diff --git a/tmac/andoc.tmac b/tmac/andoc.tmac
index ed12da8..1e6f105 100644
--- a/tmac/andoc.tmac
+++ b/tmac/andoc.tmac
@@ -60,6 +60,8 @@
 .  do als em andoc-em
 .  do als bp andoc-bp
 .  do als ne andoc-ne
+.  do blm            \" no blank line trap
+.  do lsm            \" no leading space trap
 .
 .  do rm Dd          \" force reinitialization of doc.tmac
 .  do mso doc.tmac
@@ -81,7 +83,7 @@
 .
 .  do als em andoc-em
 .  do als bp andoc-bp
-.  do blm            \" no blank line macro
+.  do blm            \" no blank line trap
 .
 .  do rm TH          \" force reinitialization of an-old.tmac
 .  do mso an-old.tmac