Make overriding cnf-handler work

See #1925: This allows users to disable the cnf-logic which can be quite
slow on small hardware (like a raspberry pi).

Squashed commit of the following:

commit 742a59e30d8db24b6bb5067d4204d4b5cc01c1c3
Author: Fabian Homborg <FHomborg@gmail.com>
Date:   Sun Aug 30 18:23:41 2015 +0200

    Erase startup cnf-handler early

    Simplifies the code a bit - in particular it removes the special-casing
    from the startup handler.

commit 638a97e7f31f302b65e044c93c638c03a69e31f5
Author: Fabian Homborg <FHomborg@gmail.com>
Date:   Mon Aug 24 20:14:46 2015 +0200

    Make overriding cnf-handler work

    Do this by renaming the __fish_command_not_found_handler used during
    startup to __fish_startup_command_not_found_handler. That allows us to
    check if __fish_command_not_found_handler has been defined and skip the
    setup of the normal one.

    Now disabling cnf-handling can be done via defining an empty
    __fish_command_not_found_handler in config.fish

1 files changed, 7 insertions, 5 deletions

diff --git a/share/functions/__fish_config_interactive.fish b/share/functions/__fish_config_interactive.fish
index fa1e140d..e9e2d912 100644
--- a/share/functions/__fish_config_interactive.fish
+++ b/share/functions/__fish_config_interactive.fish
@@ -196,17 +196,19 @@ function __fish_config_interactive -d "Initializations that should be performed
 		end
 	end
 
-	# The first time a command is not found, look for command-not-found
-	# This is not cheap so we try to avoid doing it during startup
-	# config.fish already installed a handler for noninteractive command-not-found,
-	# so delete it here since we are now interactive
-	functions -e __fish_command_not_found_handler
+	# Remove the startup command_not_found handler since we're done with it
+	functions -e __fish_startup_command_not_found_handler
 
 	# Now install our fancy variant
 	function __fish_command_not_found_setup --on-event fish_command_not_found
 		# Remove fish_command_not_found_setup so we only execute this once
 		functions --erase __fish_command_not_found_setup
 
+		# If the user defined a handler, it takes precedence
+		# It does not need to be executed because it's been defined before the event
+		if type -q __fish_command_not_found_handler
+			return 0
+		end
 		# First check if we are on OpenSUSE since SUSE's handler has no options
 		# and expects first argument to be a command and second database
 		# also check if there is command-not-found command.