[PATCH] log -L: improve error message on malformed argument

[Matthieu Moy <Matthieu.Moy@imag.fr>]

The old message did not mention the :regex:file form.

To avoid overly long lines, split the message into two lines (in case
item->string is long, it will be the only part truncated in a narrow
terminal).

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 line-log.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/line-log.c b/line-log.c
index a490efe..e725248 100644
--- a/line-log.c
+++ b/line-log.c
@@ -575,7 +575,8 @@ parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
 
 		name_part = skip_range_arg(item->string);
 		if (!name_part || *name_part != ':' || !name_part[1])
-			die("-L argument '%s' not of the form start,end:file",
+			die("invalid -L argument '%s'.\n"
+			    "It should be of the form start,end:file or :regex:file.",
 			    item->string);
 		range_part = xstrndup(item->string, name_part - item->string);
 		name_part++;
-- 
2.4.0.rc1.42.g9642cc6