Bash 5.1: Completion bug fix

[Marc Aurèle La France]

Fix a bug in attempt_shell_completion() since 4.3-beta that allows the
programmable completion code to override a prior decision made by
attempt_shell_completion() that command completion is >not< to be used.

A test case (the simplest of two possible) follows.

Please Reply-To-All.

Thanks.

Marc.

--

In an empty directory, do ...

touch aaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Then (where [tab] means the TAB key) ...

echo >& [tab]        # correctly gives the above touch'ed filename
echo >& a[tab][tab]  # gives a list of commands that start with "a"
echo >& aa[tab][tab] # gives a list of commands that start with "aa"

.. and so on, until the aa... string is long enough to not match any
command, at which point the touch'ed filename is correctly displayed.

--
--- bash-5.1/bashline.c
+++ devel-5.1/bashline.c
@@ -1560,7 +1560,7 @@ attempt_shell_completion (text, start, end)
       in_command_position++;

       if (check_redir (ti) == 1)
-       in_command_position = 0;
+       in_command_position = -1;       /* No override */
     }
   else
     {
@@ -1569,7 +1569,7 @@ attempt_shell_completion (text, start, end)
         assignments. */
     }

-  if (in_command_position && invalid_completion (text, ti))
+  if (in_command_position > 0 && invalid_completion (text, ti))
     {
       rl_attempted_completion_over = 1;
       return ((char **)NULL);
@@ -1577,9 +1577,9 @@ attempt_shell_completion (text, start, end)

   /* Check that we haven't incorrectly flagged a closed command substitution
      as indicating we're in a command position. */
-  if (in_command_position && ti >= 0 && rl_line_buffer[ti] == '`' &&
+  if (in_command_position > 0 && ti >= 0 && rl_line_buffer[ti] == '`' &&
        *text != '`' && unclosed_pair (rl_line_buffer, end, "`") == 0)
-    in_command_position = 0;
+    in_command_position = -1;          /* No override */

   /* Special handling for command substitution.  If *TEXT is a backquote,
      it can be the start or end of an old-style command substitution, or
@@ -1587,8 +1587,9 @@ attempt_shell_completion (text, start, end)
      succeed.  Don't bother if readline found a single quote and we are
      completing on the substring.  */
   if (*text == '`' && rl_completion_quote_character != '\'' &&
-       (in_command_position || (unclosed_pair (rl_line_buffer, start, "`") &&
-                                unclosed_pair (rl_line_buffer, end, "`"))))
+       (in_command_position > 0 ||
+               (unclosed_pair (rl_line_buffer, start, "`") &&
+                unclosed_pair (rl_line_buffer, end, "`"))))
     matches = rl_completion_matches (text, command_subst_completion_function);

 #if defined (PROGRAMMABLE_COMPLETION)
@@ -1596,7 +1597,8 @@ attempt_shell_completion (text, start, end)
   have_progcomps = prog_completion_enabled && (progcomp_size () > 0);
   iw_compspec = progcomp_search (INITIALWORD);
   if (matches == 0 &&
-      (in_command_position == 0 || text[0] == '\0' || (in_command_position && 
iw_compspec)) &&
+      (in_command_position == 0 || text[0] == '\0' ||
+       (in_command_position > 0 && iw_compspec)) &&
       current_prompt_string == ps1_prompt)
     {
       int s, e, s1, e1, os, foundcs;
@@ -1718,7 +1720,7 @@ attempt_shell_completion (text, start, end)
   if (matches == 0)
     {
       dflags = 0;
-      if (in_command_position)
+      if (in_command_position > 0)
        dflags |= DEFCOMP_CMDPOS;
       matches = bash_default_completion (text, start, end, qc, dflags);
     }