[completion] GDB completion bug

[completion] GDB completion bug

[Arusekk]

Hello!

This is my first time with zsh development, so I hope I will not miss 
anything. I am using zsh 5.8 shipped with Gentoo, no patches.
I use oh-my-zsh with plugins=(tig gitfast colored-man-pages colorize 
command-not-found cp dirhistory autojump sudo fast-syntax-highlighting 
zsh-autosuggestions)
and ZSH_THEME="powerlevel10k/powerlevel10k" and no further 
customisations, but I hope this is irrelevant, just activates the 
completion functions.

The bug is not critical in any way, but just happens in the following 
setting:

zsh-5.8% gdb (cursor here) -h

Then it is enough to hit Tab. The -h can be any other option, or even a 
file name, not really important, but there has to be space before 
cursor, and after it (I guess so).

This is the error message:

_pids:shift:13: shift count must be <= $#
_pids:compadd:42: bad option: -m

I traced it down to most probably 
/usr/share/zsh/5.8/functions/Completion/Unix/_gdb calling _pids, but I 
do not know enough of zsh completion to investigate more.

Glad to have found a bug in such reliable software!
Arusekk

Re: [completion] GDB completion bug

[Daniel Shahaf]

Arusekk wrote on Sun, Nov 22, 2020 at 23:39:53 +0100:
> _pids:shift:13: shift count must be <= $#
> _pids:compadd:42: bad option: -m

I can reproduce this.

> I traced it down to most probably
> /usr/share/zsh/5.8/functions/Completion/Unix/_gdb calling _pids, but I do
> not know enough of zsh completion to investigate more.

fned it and add «typeset -p w >/dev/tty» right before the call and
you'll see that w=('' -h) at that point; then, the parameter expansion
in the call to _pids isn't quoted and expands to an empty string, hence
it's elided, causing the error.

Unsure of the fix.

Cheers,

Daniel

> Glad to have found a bug in such reliable software!
> Arusekk
> 
> 

Re: [completion] GDB completion bug

[Oliver Kiddle]

On 22 Nov, Arusekk wrote:
> The bug is not critical in any way, but just happens in the following 
> setting:
>
> zsh-5.8% gdb (cursor here) -h

> _pids:shift:13: shift count must be <= $#
> _pids:compadd:42: bad option: -m

In this case, I think we can fix this by limiting the search of the
$words array to words preceding the cursor as in the following patch.
I've also updated somewhat the pattern for options that might take
an argument in a following word.

In general, gdb completion could be improved quite a bit more.

> Glad to have found a bug in such reliable software!
> Arusekk

Thanks for reporting this and sorry for not dealing with it sooner.

Oliver

diff --git a/Completion/Unix/Command/_gdb b/Completion/Unix/Command/_gdb
index 18f797633..6bdd55946 100644
--- a/Completion/Unix/Command/_gdb
+++ b/Completion/Unix/Command/_gdb
@@ -40,9 +40,9 @@ else
   (-b)     _baudrates && return 0 ;;
   esac
 
-  w=( "${(@)words[2,-1]}" )
+  w=( "${(@)words[2,CURRENT-1]}" )
   while [[ "$w[1]" = -* ]]; do
-    [[ "$w[1]" = -[decsxb] ]] && shift 1 w
+    [[ "$w[1]" = -(cd|se|tty|[decsxb]) ]] && shift 1 w
     shift 1 w
   done