Do not break output lines in .Fn function arguments in SYNOPSIS mode.

Following an idea from Franco Fichtner, but implemented more cleanly.
This reduces groff-mandoc-differences in OpenBSD base by a fantastic 7.5%.

1 files changed, 10 insertions, 0 deletions

diff --git a/mdoc_man.c b/mdoc_man.c
index 8ea1e166..d21cad56 100644
--- a/mdoc_man.c
+++ b/mdoc_man.c
@@ -256,6 +256,7 @@ static	int		outflags;
 #define	MMAN_An_split	(1 << 9)  /* author mode is "split" */
 #define	MMAN_An_nosplit	(1 << 10) /* author mode is "nosplit" */
 #define	MMAN_PD		(1 << 11) /* inter-paragraph spacing disabled */
+#define	MMAN_nbrword	(1 << 12) /* do not break the next word */
 
 #define	BL_STACK_MAX	32
 
@@ -364,6 +365,12 @@ print_word(const char *s)
 		case (ASCII_HYPH):
 			putchar('-');
 			break;
+		case (' '):
+			if (MMAN_nbrword & outflags) {
+				printf("\\ ");
+				break;
+			}
+			/* FALLTHROUGH */
 		default:
 			putchar((unsigned char)*s);
 			break;
@@ -371,6 +378,7 @@ print_word(const char *s)
 		if (TPremain)
 			TPremain--;
 	}
+	outflags &= ~MMAN_nbrword;
 }
 
 static void
@@ -1028,6 +1036,8 @@ pre_fa(DECL_ARGS)
 
 	while (NULL != n) {
 		font_push('I');
+		if (MDOC_SYNPRETTY & n->flags)
+			outflags |= MMAN_nbrword;
 		print_node(meta, n);
 		font_pop();
 		if (NULL != (n = n->next))