[groff] 10/16: [troff]: Trivially refactor (boolify begin_page).

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit c42b396a21abec2454bcfd105220461266f35ab0
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Mon Jan 8 10:05:07 2024 -0600

    [troff]: Trivially refactor (boolify begin_page).
    
    * src/roff/troff/div.cpp (top_level_diversion::begin_page): Demote
      return type from `int` to `bool`.  Return Boolean instead of integer
      literals.
    
    * src/roff/troff/div.h (class top_level_diversion): Update declaration.
    
    Also:
    Wrap long lines.  Annotate null pointers with `nullptr` comment to ease
    any future transition to C++11, which defines it as a keyword.
---
 ChangeLog              | 11 +++++++++++
 src/roff/troff/div.cpp | 15 ++++++++-------
 src/roff/troff/div.h   |  2 +-
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index fcbf260cb..437f38ef1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2024-01-08  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       [troff]: Trivially refactor.
+
+       * src/roff/troff/div.cpp (top_level_diversion::begin_page):
+       Demote return type from `int` to `bool`.  Return Boolean instead
+       of integer literals.
+
+       * src/roff/troff/div.h (class top_level_diversion): Update
+       declaration.
+
 2024-01-08  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        [troff]: Enhance new tests.
diff --git a/src/roff/troff/div.cpp b/src/roff/troff/div.cpp
index da6a00282..36cf11773 100644
--- a/src/roff/troff/div.cpp
+++ b/src/roff/troff/div.cpp
@@ -601,9 +601,9 @@ void cleanup_and_exit(int exit_code)
   exit(exit_code);
 }
 
-// Returns non-zero if it sprung a top-of-page trap.
+// Returns `true` if beginning the page sprung a top-of-page trap.
 // The optional parameter is for the .trunc register.
-int top_level_diversion::begin_page(vunits n)
+bool top_level_diversion::begin_page(vunits n)
 {
   if (is_exit_underway) {
     if (page_count == last_page_count
@@ -634,19 +634,20 @@ int top_level_diversion::begin_page(vunits n)
   vertical_position = V0;
   high_water_mark = V0;
   ejecting_page = 0;
-  // If before_first_page was 2, then the top of page transition was undone
-  // using eg .nr nl 0-1.  See nl_reg::set_value.
+  // If before_first_page was 2, then the top of page transition was
+  // undone using eg .nr nl 0-1.  See nl_reg::set_value.
   if (before_first_page != 2)
     the_output->begin_page(page_number, page_length);
   before_first_page = 0;
   nl_reg_contents = vertical_position.to_units();
-  if (vertical_position_traps_flag && next_trap != 0 && next_trap_pos == V0) {
+  if ((vertical_position_traps_flag && next_trap != 0 /* nullptr */)
+      && next_trap_pos == V0) {
     truncated_space = n;
     spring_trap(next_trap->nm);
-    return 1;
+    return true;
   }
   else
-    return 0;
+    return false;
 }
 
 void continue_page_eject()
diff --git a/src/roff/troff/div.h b/src/roff/troff/div.h
index 6180caa0b..1ffc8cc23 100644
--- a/src/roff/troff/div.h
+++ b/src/roff/troff/div.h
@@ -137,7 +137,7 @@ public:
   int get_page_number() { return page_number; }
   int get_next_page_number();
   void set_page_number(int n) { page_number = n; }
-  int begin_page(vunits = V0);
+  bool begin_page(vunits = V0);
   void set_next_page_number(int);
   void set_page_length(vunits);
   void copy_file(const char *filename);