[groff] 04/41: [me]: Fix Savannah #62181.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit a7853c5b5bb975a6e058238405bb0080a9a4a19a
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Tue Mar 15 18:17:42 2022 +1100

    [me]: Fix Savannah #62181.
    
    * tmac/e.tmac: Test register for existence before using it to set
      hyphenation mode.  A site troffrc or other local customization might
      remove the register (which is guaranteed to be set under the stock
      configuration) and, perversely, Heirloom Doctools troff interprets a
      `do` request, instead of ignoring it as a historical troff
      implementation would, so if they borrow our me(7) changes, the
      register would be unset, interpolate zero, and hyphenation would wind
      up disabled.
    
    Fixes <https://savannah.gnu.org/bugs/?62181>.  Thanks to Dave Kemper for
    the report.
---
 ChangeLog   | 14 ++++++++++++++
 tmac/e.tmac |  3 ++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 7c9c18fc..4a1e4054 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2022-03-15  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       * tmac/e.tmac: Test register for existence before using it to
+       set hyphenation mode.  A site troffrc or other local
+       customization might remove the register (which is guaranteed to
+       be set under the stock configuration) and, perversely, Heirloom
+       Doctools troff interprets a `do` request, instead of ignoring it
+       as a historical troff implementation would, so if they borrow
+       our me(7) changes, the register would be unset, interpolate
+       zero, and hyphenation would wind up disabled.
+
+       Fixes <https://savannah.gnu.org/bugs/?62181>.  Thanks to Dave
+       Kemper for the report.
+
 2022-03-14  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        [tests]: Rename test to apply naming scheme.
diff --git a/tmac/e.tmac b/tmac/e.tmac
index aca80fce..acf50926 100644
--- a/tmac/e.tmac
+++ b/tmac/e.tmac
@@ -2010,7 +2010,8 @@
 .\" Set package default hyphenation mode, but override it with groff's
 .\" localized value if available.
 .hy 6
-.do hy \\n[\\*[locale]*hyphenation-mode-trap]
+.do if r \\*[locale]*hyphenation-mode-trap \
+.  do hy \\n[\\*[locale]*hyphenation-mode-trap]
 ..
 .
 .ld