Refactor the handler function roff_block_sub() for clarity and simplicity.

1. Do not needlessly access the function pointer table roffs[].
Instead, simply call the block closing function directly.

2. Sort code: handle both cases of block closing at the beginning
of the function rather than one at the beginning and one at the end.

3. Trim excessive, partially repetitive and obvious comments, also
making the comments considerably more precise.

No functional change.

1 files changed, 10 insertions, 17 deletions

diff --git a/usr.bin/mandoc/roff.c b/usr.bin/mandoc/roff.c
index bbb1b6fb0eb..4ec15aa3492 100644
--- a/usr.bin/mandoc/roff.c
+++ b/usr.bin/mandoc/roff.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: roff.c,v 1.256 2022/04/28 16:16:46 schwarze Exp $ */
+/* $OpenBSD: roff.c,v 1.257 2022/04/30 11:32:39 schwarze Exp $ */
 /*
  * Copyright (c) 2010-2015, 2017-2022 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
@@ -2274,12 +2274,8 @@ roff_block_sub(ROFF_ARGS)
 	int		i, j;
 
 	/*
-	 * First check whether a custom macro exists at this level.  If
-	 * it does, then check against it.  This is some of groff's
-	 * stranger behaviours.  If we encountered a custom end-scope
-	 * tag and that tag also happens to be a "real" macro, then we
-	 * need to try interpreting it again as a real macro.  If it's
-	 * not, then return ignore.  Else continue.
+	 * If a custom end marker is a user-defined or predefined macro
+	 * or a request, interpret it.
 	 */
 
 	if (r->last->end) {
@@ -2305,20 +2301,17 @@ roff_block_sub(ROFF_ARGS)
 		}
 	}
 
-	/*
-	 * If we have no custom end-query or lookup failed, then try
-	 * pulling it out of the hashtable.
-	 */
+	/* Handle the standard end marker. */
 
 	t = roff_parse(r, buf->buf, &pos, ln, ppos);
+	if (t == ROFF_cblock)
+		return roff_cblock(r, t, buf, ln, ppos, pos, offs);
 
-	if (t != ROFF_cblock) {
-		if (tok != ROFF_ig)
-			roff_setstr(r, r->last->name, buf->buf + ppos, 2);
-		return ROFF_IGN;
-	}
+	/* Not an end marker, so append the line to the block. */
 
-	return (*roffs[t].proc)(r, t, buf, ln, ppos, pos, offs);
+	if (tok != ROFF_ig)
+		roff_setstr(r, r->last->name, buf->buf + ppos, 2);
+	return ROFF_IGN;
 }
 
 static int