Fix asan errors

It found some really nasty ones :)

1 files changed, 6 insertions, 1 deletions

diff --git a/src/dged/text.c b/src/dged/text.c
index 0a92933..82c49bc 100644
--- a/src/dged/text.c
+++ b/src/dged/text.c
@@ -77,9 +77,14 @@ void text_clear(struct text *text) {
 
 // given `char_idx` as a character index, return the byte index
 uint32_t charidx_to_byteidx(struct line *line, uint32_t char_idx) {
+  if (line->nchars == 0) {
+    return 0;
+  }
+
   if (char_idx > line->nchars) {
-    return line->nbytes;
+    return line->nbytes - 1;
   }
+
   return utf8_nbytes(line->data, line->nbytes, char_idx);
 }