(internal_self_insert): Only set TARGET_CLM when C2 is tab.

When multibyte characters are disabled,
use 1 as the width of the inserted character.

diff --git a/src/cmds.c b/src/cmds.c
index fac3791794fea82499799e9a95f7d735ccf7a8c9..70dfbceb7f0ecba4ddb92f8824ed89043b5c74fd 100644 (file)
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -396,20 +396,21 @@ internal_self_insert (c, noautofill)
          The correct value should be calculated only when necessary.  */
       int target_clm = 0;
 
-      /* Overwriting in binary-mode always substitute C2 by C.  But,
-        overwriting in textual-mode does this substitution in the
-        case that C is not NEWLINE and C2 is not NEWLINE nor TAB.  If
-        C2 is TAB, the substitution is done only when C2 is currently
-        expanded to 0 column, or more than 20 columns, or more than
-        the width of C.  */
+      /* Overwriting in binary-mode always replaces C2 by C.
+        Overwriting in textual-mode doesn't always do that.
+        It inserts newlines in the usual way,
+        and inserts any character at end of line
+        or before a tab if it doesn't use the whole width of the tab.  */
       if (EQ (overwrite, Qoverwrite_mode_binary)
          || (c != '\n'
              && c2 != '\n'
-             && (target_clm = current_column() + WIDTH_BY_CHAR_HEAD (str[0]),
-                 (c2 != '\t'
-                  || XINT (current_buffer->tab_width) <= 0
-                  || XFASTINT (current_buffer->tab_width) > 20
-                  || !(target_clm % XFASTINT (current_buffer->tab_width))))))
+             && ! (c2 == '\t'
+                   && XINT (current_buffer->tab_width) > 0
+                   && XFASTINT (current_buffer->tab_width) < 20
+                   && ((NILP (current_buffer->enable_multibyte_characters)
+                        ? (target_clm = current_column () + 1)
+                        : (target_clm = current_column () + WIDTH_BY_CHAR_HEAD (str[0]))),
+                       target_clm % XFASTINT (current_buffer->tab_width)))))
        {
          int pos = PT;