[groff] 11/16: [troff]: Clarify diagnostic messages.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit a8be5f9dba98ab1f8c90de5c6c8e86971b94a540
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Mon Jan 8 10:25:07 2024 -0600

    [troff]: Clarify diagnostic messages.
    
    * src/roff/troff/div.cpp (top_level_diversion::output)
      (top_level_diversion::transparent_output)
      (top_level_diversion::copy_file): Clarify diagnostic messages.
    
    They are lengthy--troff is not a simple machine, alas.
---
 ChangeLog              |  6 ++++++
 src/roff/troff/div.cpp | 15 ++++++++-------
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 437f38ef1..6c0fde1ce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2024-01-08  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       * src/roff/troff/div.cpp (top_level_diversion::output)
+       (top_level_diversion::transparent_output)
+       (top_level_diversion::copy_file): Clarify diagnostic messages.
+
 2024-01-08  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        [troff]: Trivially refactor.
diff --git a/src/roff/troff/div.cpp b/src/roff/troff/div.cpp
index 36cf11773..6ac9ef017 100644
--- a/src/roff/troff/div.cpp
+++ b/src/roff/troff/div.cpp
@@ -400,8 +400,9 @@ void top_level_diversion::output(node *nd, int retain_size,
   vunits next_trap_pos;
   trap *next_trap = find_next_trap(&next_trap_pos);
   if (before_first_page && begin_page())
-    fatal("attempting diversion output before first page has started;"
-         " invoke break or flush request earlier");
+    fatal("attempting diversion output before first page has started,"
+         " when a top-of-page trap is defined; invoke break or flush"
+         " request beforehand");
   vertical_size v(vs, post_vs);
   for (node *tem = nd; tem != 0; tem = tem->next)
     tem->set_vertical_size(&v);
@@ -449,9 +450,9 @@ void top_level_diversion::output(node *nd, int retain_size,
 void top_level_diversion::transparent_output(unsigned char c)
 {
   if (before_first_page && begin_page())
-    fatal("attempting transparent output of top-level diversion before"
-         " first page has started; invoke break or flush request"
-         " earlier");
+    fatal("attempting transparent output from top-level diversion"
+         " before first page has started, when a top-of-page trap is"
+         " defined; invoke break or flush request beforehand");
   const char *s = asciify(c);
   while (*s)
     the_output->transparent_char(*s++);
@@ -470,8 +471,8 @@ void top_level_diversion::copy_file(const char *filename)
 {
   if (before_first_page && begin_page())
     fatal("attempting transparent copy of file to top-level diversion"
-         " before first page has started; invoke break or flush"
-         " request earlier");
+         " before first page has started, when a top-of-page trap is"
+         " defined; invoke break or flush request beforehand");
   the_output->copy_file(page_offset, vertical_position, filename);
 }