[groff] 03/15: [troff]: Warn better when .composite lacks args.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 750daf5b419da49b57724743b82214f2615eac9b
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Tue Nov 28 18:49:52 2023 -0600

    [troff]: Warn better when .composite lacks args.
    
    * src/roff/troff/input.cpp (composite_request): Throw warning diagnostic
      if either argument is absent; stop relying upon `get_name()` to do so,
      which is a slight abuse since we don't regard the arguments to this
      request as "identifiers" (how they're described in its diagnostic
      messages).  Instead test retrieved symbol for nullity and throw a more
      contextful message.
    
    This commit omits updates to indentation to clarify the logic change.
---
 ChangeLog                | 10 ++++++++++
 src/roff/troff/input.cpp | 21 ++++++++++++++-------
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 0a68b9d6e..616de4511 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2023-11-28  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       * src/roff/troff/input.cpp (composite_request): Throw warning
+       diagnostic if either argument is absent; stop relying upon
+       `get_name()` to do so, which is a slight abuse since we
+       don't regard the arguments to this request as "identifiers"
+       {how they're described in its diagnostic messages}.  Instead
+       test retrieved symbol for nullity and throw a more contextful
+       message.
+
 2023-11-28  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * src/roff/troff/input.cpp (char_flags): Rename to...
diff --git a/src/roff/troff/input.cpp b/src/roff/troff/input.cpp
index 7a70722ab..8a92553e2 100644
--- a/src/roff/troff/input.cpp
+++ b/src/roff/troff/input.cpp
@@ -4113,8 +4113,13 @@ dictionary composite_dictionary(17);
 
 void composite_request()
 {
-  symbol from = get_name(true /* required */);
-  if (!from.is_null()) {
+  symbol from = get_name();
+  if (from.is_null()) {
+    warning(WARN_MISSING, "composite character request expects"
+           " arguments");
+    skip_line();
+    return;
+  }
     const char *from_gn = glyph_name_to_unicode(from.contents());
     if (!from_gn) {
       from_gn = check_unicode_name(from.contents());
@@ -4127,10 +4132,14 @@ void composite_request()
     const char *from_decomposed = decompose_unicode(from_gn);
     if (from_decomposed)
       from_gn = &from_decomposed[1];
-    symbol to = get_name(true /* required */);
-    if (to.is_null())
+    symbol to = get_name();
+    if (to.is_null()) {
       composite_dictionary.remove(symbol(from_gn));
-    else {
+      warning(WARN_MISSING, "composite character request expects two"
+             " arguments");
+      skip_line();
+      return;
+    }
       const char *to_gn = glyph_name_to_unicode(to.contents());
       if (!to_gn) {
        to_gn = check_unicode_name(to.contents());
@@ -4147,8 +4156,6 @@ void composite_request()
        composite_dictionary.remove(symbol(from_gn));
       else
        (void)composite_dictionary.lookup(symbol(from_gn), (void *)to_gn);
-    }
-  }
   skip_line();
 }