From d6d3b6b233e85027dc0b286e22fe9bd1dc430bc9 Mon Sep 17 00:00:00 2001
From: David Kastrup <dak@gnu.org>
Date: Tue, 11 Dec 2012 10:20:20 +0100
Subject: [PATCH] Issue 3012: Flag an error for isolated post-events occuring
 in music lists

These can happen when writing things like

c \tweak #'color #red -3

since at the current point of time a tweaked post-event is not
syntactically recognized as a post-event without leading -, like

c -\tweak #'color #red -3

While this restriction will at some time be removed, in the mean time
we want to have this problem flagged.
---
 lily/parser.yy | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/lily/parser.yy b/lily/parser.yy
index d6a7beac92..77075a2882 100644
--- a/lily/parser.yy
+++ b/lily/parser.yy
@@ -1017,13 +1017,24 @@ music:	music_arg
 
 music_embedded:
 	music
+	{
+		if (unsmob_music ($1)->is_mus_type ("post-event")) {
+			parser->parser_error (@1, _ ("unexpected post-event"));
+			$$ = SCM_UNSPECIFIED;
+		}
+	}
 	| embedded_scm
 	{
-		if (unsmob_music ($1)
-		    || scm_is_eq ($1, SCM_UNSPECIFIED))
+		if (scm_is_eq ($1, SCM_UNSPECIFIED))
 			$$ = $1;
-		else
-		{
+		else if (Music *m = unsmob_music ($1)) {
+			if (m->is_mus_type ("post-event")) {
+				parser->parser_error
+					(@1, _ ("unexpected post-event"));
+				$$ = SCM_UNSPECIFIED;
+			} else
+				$$ = $1;
+		} else {
 			@$.warning (_ ("Ignoring non-music expression"));
 			$$ = SCM_UNSPECIFIED;
 		}
-- 
2.39.2