diff -upr libpipeline-1.2.2.orig/lib/pipeline.c libpipeline-1.2.2/lib/pipeline.c
--- libpipeline-1.2.2.orig/lib/pipeline.c	2012-03-04 18:43:07.000000000 +0100
+++ libpipeline-1.2.2/lib/pipeline.c	2012-11-30 14:46:14.395724863 +0100
@@ -2168,8 +2168,13 @@ const char *pipeline_readline (pipeline
 {
 	size_t buflen;
 	const char *buffer = get_line (p, &buflen);
-	if (buffer)
-		p->peek_offset -= buflen;
+	if (buffer) {
+		if (p->peek_offset > buflen) {
+			p->peek_offset -= buflen;
+		} else {
+			p->peek_offset = 0;
+		}
+	}
 	return buffer;
 }