39566: Improve usefulness of command_not_found_handler.

Don't behave as if command not found if return status is non-zero

as this may simply be the return status of the replacement command.
Let the function report a command not found instead.

1 files changed, 8 insertions, 7 deletions

diff --git a/Doc/Zsh/exec.yo b/Doc/Zsh/exec.yo
index 30e4a61a2..5f79967de 100644
--- a/Doc/Zsh/exec.yo
+++ b/Doc/Zsh/exec.yo
@@ -28,10 +28,11 @@ not handle this executable format in the kernel.
 
 If no external command is found but a function tt(command_not_found_handler)
 exists the shell executes this function with all
-command line arguments.  The function should return status zero if it
-successfully handled the command, or non-zero status if it failed.
-In the latter case the standard handling is applied: `command not
-found' is printed to standard error and the shell exits with status 127.
-Note that the handler is executed in a subshell forked to execute
-an external command, hence changes to directories, shell parameters,
-etc. have no effect on the main shell.
+command line arguments.  The return status of the function becomes the
+status of the command.  If the function wishes to mimic the
+behaviour of the shell when the command is not found, it should
+print the message `tt(command not found:) var(cmd)' to standard error
+and return status 127.  Note that the handler is executed in a
+subshell forked to execute an external command, hence changes to
+directories, shell parameters, etc. have no effect on the main shell.
+