Only use the global fish_complete_path and fish_function_path

Prior to this fix, fish would attempt to react if a local fish_complete_path
or fish_function_path were set. However this has never been very well tested
and will become impossible with concurrent execution. Always use the global
values.

CHANGELOG.md

@@ -17,6 +17,7 @@
 - Some parser errors did not set `$status` to non-zero. This has been corrected (b2a1da602f79878f4b0adc4881216c928a542608).
 - `string` has a new `collect` subcommand that disables newline-splitting on its input. This is meant to be used as the end of a command substitution pipeline to produce a single output argument potentially containing internal newlines, such as `set output (some-cmd | string collect)`. Any trailing newlines are trimmed, just like `"$(cmd)"` substitution in sh. It also supports a `--no-trim-newlines` flag to disable trailing newline trimming, which may be useful when doing something like `set contents (cat filename | string collect -N)` (#159).
 - More of the documentation, including the tutorial, is now available as man pages as well.
+- Local values for `fish_complete_path` and `fish_function_path` are now ignored; only their global values are respected.
 
 ### Syntax changes and new commands
 - Brace expansion now only takes place if the braces include a "," or a variable expansion, so things like `git reset HEAD@{0}` now work (#5869).

src/complete.cpp

@@ -873,8 +873,9 @@ static void complete_load(const wcstring &name) {
     // It's important to NOT hold the lock around completion loading.
     // We need to take the lock to decide what to load, drop it to perform the load, then reacquire
     // it.
-    const environment_t &vars = parser_t::principal_parser().vars();
-    maybe_t<wcstring> path_to_load = completion_autoloader.acquire()->resolve_command(name, vars);
+    // Note we only look at the global fish_function_path and fish_completion_path.
+    maybe_t<wcstring> path_to_load =
+        completion_autoloader.acquire()->resolve_command(name, env_stack_t::globals());
     if (path_to_load) {
         autoload_t::perform_autoload(*path_to_load, parser);
         completion_autoloader.acquire()->mark_autoload_finished(name);

src/function.cpp

@@ -104,7 +104,7 @@ static void try_autoload(const wcstring &name, parser_t &parser) {
     {
         auto funcset = function_set.acquire();
         if (funcset->allow_autoload(name)) {
-            path_to_autoload = funcset->autoloader.resolve_command(name, parser.vars());
+            path_to_autoload = funcset->autoloader.resolve_command(name, env_stack_t::globals());
         }
     }