Effect of "print -s" when called in zle widget not seen until zle is restarted

[Stephane Chazelas <stephane@xxxxxxxxxxxx>]

From
https://unix.stackexchange.com/questions/583443/adding-a-string-to-the-zsh-history

User https://unix.stackexchange.com/users/368116/noibe:
> The following function
> 
> function test_hist() {
>     print -s "This is a test"
> }
> zle -N test_hist
> bindkey '^X^T' test_hist
> 
> adds the string This is a test to the zsh-history.
> 
> If I call the function explicitly by typing test_hist, the
> string is immediately added to the history, but if I call it
> through the bindkey by pressing ctrl-x ctrl-t, the string is not
> added to the history straight away. I need to issue another
> command before I can see it in the history.
> 
> Why is that, and how can I fix it?

My answer there:

I find that using fc -R =(print text) in place of print -s text
works consistently in and out of a zle widgets though, so it
could be a work around for you.

Looking at the code of zsh 5.8, I find that fc -R seems to let
zle know that a new history entry has been added when it detects
zle is active, while print -s doesn't.

This patch (on the current git head as of
2020-05-02T22:20+01:00) seems to fix it:

diff --git a/Src/builtin.c b/Src/builtin.c
index 3dab3f9b4..551653508 100644
--- a/Src/builtin.c
+++ b/Src/builtin.c
@@ -4918,6 +4918,8 @@ bin_print(char *name, char **args, Options ops, int func)
 	    ent->stim = ent->ftim = time(NULL);
 	    ent->node.flags = 0;
 	    addhistnode(histtab, ent->node.nam, ent);
+	    if (zleactive)
+		zleentry(ZLE_CMD_SET_HIST_LINE, curhist);
 	    unqueue_signals();
 	    return 0;
 	}

Not sure if that's the right fix though. I'll submit it to
zsh-workers@xxxxxxx.

Hence this email.

-- 
Stephane