When undoing, delete space only if there is a space.

Attached and glued strokes don't emit spaces. So, we cannot mindlessly
delete the last character without checking if it is a space.

* thogai.el (thogai-insert-stroke): When undoing, delete space only if
there actually is a space.

1 files changed, 4 insertions, 2 deletions

diff --git a/thogai.el b/thogai.el
index 8e1f5be..b863018 100644
--- a/thogai.el
+++ b/thogai.el
@@ -317,10 +317,12 @@ should typically be `thogai-stroke-ring'."
           ;; Reverse the previous group of strokes.
           (thogai-reverse-strokes matched-strokes)
           ;; Delete space before strokes unless we are at the
-          ;; beginning of the line.
+          ;; beginning of the line. Note that attached and glued
+          ;; strokes do not emit spaces. So, we cannot mindlessly
+          ;; delete a character without checking if it is a space.
           (unless (= (line-beginning-position)
                      (point))
-            (delete-char -1))
+            (thogai-delete " "))
           ;; Re-insert the previous group of strokes except for the
           ;; newest stroke.
           (pcase (reverse matched-strokes)