Merge text0

edit.lua

@@ -78,7 +78,7 @@ function edit.check_locs(State)
   -- if State is inconsistent (i.e. file changed by some other program),
   --   throw away all cursor state entirely
   if edit.invalid1(State, State.screen_top1)
-      or edit.invalid1(State, State.cursor1)
+      or edit.invalid_cursor1(State)
       or not Text.le1(State.screen_top1, State.cursor1) then
     State.screen_top1 = {line=1, pos=1}
     State.cursor1 = {line=1, pos=1}
@@ -92,6 +92,16 @@ function edit.invalid1(State, loc1)
   return loc1.pos > #State.lines[loc1.line].data
 end
 
+-- cursor loc in particular differs from other locs in one way:
+-- pos might occur just after end of line
+function edit.invalid_cursor1(State)
+  local cursor1 = State.cursor1
+  if cursor1.line > #State.lines then return true end
+  local l = State.lines[cursor1.line]
+  if l.mode ~= 'text' then return false end  -- pos is irrelevant to validity for a drawing line
+  return cursor1.pos > #State.lines[cursor1.line].data + 1
+end
+
 -- return y drawn until
 function edit.draw(State, fg, hide_cursor)
   if #State.lines ~= #State.line_cache then