Always use "." for cd

Nobody doesn't want to use $PWD to cd, so if $CDPATH does not include
it that was a mistake.

Bash also appends "." here.

Fixes #4484.

CHANGELOG.md

@@ -8,6 +8,7 @@
 - Add `$pipestatus` support
 - macOS Mojave: fish.app can actually run (#5727), 10.14.4's Terminal.app no longer causes an error on launch (#5725)
 - fish no longer requires buffering for the last function in a pipeline.
+- cd now always checks the current directory, even if $CDPATH does not include it or "." (#4484).
 
 ### Syntax changes and new commands
 - None yet.

sphinx_doc_src/cmds/cd.rst

@@ -13,7 +13,7 @@ Description
 
 If ``DIRECTORY`` is supplied, it will become the new directory. If no parameter is given, the contents of the ``HOME`` environment variable will be used.
 
-If ``DIRECTORY`` is a relative path, the paths found in the ``CDPATH`` environment variable array will be tried as prefixes for the specified path.
+If ``DIRECTORY`` is a relative path, the paths found in the ``CDPATH`` list will be tried as prefixes for the specified path, in addition to $PWD.
 
 Note that the shell will attempt to change directory without requiring ``cd`` if the name of a directory is provided (starting with ``.``, ``/`` or ``~``, or ending with ``/``).
 

src/path.cpp

@@ -173,9 +173,8 @@ maybe_t<wcstring> path_get_cdpath(const wcstring &dir, const wcstring &wd,
         if (auto cdpaths = env_vars.get(L"CDPATH")) {
             cdpathsv = cdpaths->as_list();
         }
-        if (cdpathsv.empty()) {
-            cdpathsv.push_back(L".");
-        }
+        // Always append $PWD
+        cdpathsv.push_back(L".");
         for (wcstring next_path : cdpathsv) {
             if (next_path.empty()) next_path = L".";
             if (next_path == L"." && !wd.empty()) {

tests/cd.err

@@ -7,3 +7,6 @@
 
 ####################
 # Virtual PWD inheritance
+
+####################
+# CDPATH

tests/cd.in

@@ -62,6 +62,16 @@ test (realpath $output_pwd) = $real_getcwd
 and echo "BogusPWD test 2 succeeded"
 or echo "BogusPWD test 2 failed: $output_pwd vs $real_getcwd"
 
+# $CDPATH
+logmsg CDPATH
+set -g CDPATH $base
+cd linkhome
+test $PWD = $base/linkhome; and echo Gone to linkhome via CDPATH
+set -g CDPATH /tmp
+cd $base
+test $PWD = $base; and echo Gone to base
+cd linkhome
+test $PWD = $base/linkhome; and echo Gone to linkhome via implicit . in CDPATH
 
 # cd back before removing the test directory again.
 cd $oldpwd

tests/cd.out

@@ -23,3 +23,9 @@ cd:
 PWD is /tmp/cdcomp_test/linkhome
 BogusPWD test 1 succeeded
 BogusPWD test 2 succeeded
+
+####################
+# CDPATH
+Gone to linkhome via CDPATH
+Gone to base
+Gone to linkhome via implicit . in CDPATH