Adding a string to the zsh history

Question

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?

Answer 1

I find that using fc -R =(print text) in place of print -s text works consistently in and out of a zle widget 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@zsh.org (done now).