Re: ctrl-w oddity on bash-4.4

[Eduardo A . Bustamante López]

On Wed, Oct 25, 2017 at 09:48:14AM -0400, Chet Ramey wrote:
> On 10/22/17 6:52 PM, Aron Griffis wrote:
> > I'm seeing some strange behavior and don't know if it's a bug or intended.
> > 
> > Reproducer:
> > 1. env INPUTRC=/dev/null bash --norc
> > 2. set -o vi
> > 3. true --foo=bar
> > 4. up arrow, then left arrow to put the cursor on the equals sign
> > 5. press ctrl-w, nothing happens
> 
> Posix says the word boundaries for ^W in insert mode are characters that
> aren't <blank> or <punct>. So you deal with the character before the
> cursor (`o'), and delete to a character that isn't <blank> or <punct>.
> Since the `o' is in neither character class, it's the word boundary, and
> you don't delete anything. FWIW, ksh93 behaves the same way (but beeps
> annoyingly).
[...]

Wow. I had to read the POSIX description of ^W a few times to finally
understand how this works. Thank you for the explanation Chet!



Patch for compatibility with ksh93 (just kidding!):

diff --git a/lib/readline/vi_mode.c b/lib/readline/vi_mode.c
index 3cb7e8c9..210d1b12 100644
--- a/lib/readline/vi_mode.c
+++ b/lib/readline/vi_mode.c
@@ -1615,7 +1615,14 @@ rl_vi_unix_word_rubout (int count, int key)
              rl_point--;
        }
 
-      rl_kill_text (orig_point, rl_point);
+      if (orig_point == rl_point)
+        {
+          rl_ding();
+        }
+      else
+        {
+          rl_kill_text (orig_point, rl_point);
+        }
     }
 
   return 0;