sam: fix range for line zero

 :0 < echo "Should be inserted at the start of the file"
 :1 < echo "Should replace the first line"

1 files changed, 2 insertions, 0 deletions

diff --git a/sam.c b/sam.c
index 5ebf71c..2459fa5 100644
--- a/sam.c
+++ b/sam.c
@@ -731,6 +731,8 @@ static Filerange address_line_evaluate(Address *addr, File *file, Filerange *ran
 		line = text_lineno_by_pos(txt, start);
 		line = offset < line ? text_pos_by_lineno(txt, line - offset) : 0;
 	} else {
+		if (addr->number == 0)
+			return text_range_new(0, 0);
 		line = text_pos_by_lineno(txt, addr->number);
 	}