From 892a8206727961c2c6c597bd19f4d35d58164ce5 Mon Sep 17 00:00:00 2001
From: Johannes Altmanninger <aclopte@gmail.com>
Date: Sat, 10 Dec 2022 10:56:17 +0100
Subject: [PATCH] Make sure that cd to a relative CDPATH results in absolute
 $PWD

We have had multiple crashes for relative CDPATH entries.  Commit 5e274066e
(Always return absolute path in path_get_cdpath, 2019-10-17) tried to fix
all of them but it failed to do justice to its title.  Let's fix this to
actually return absolute paths, always.  Take care to to normalize the path
because it is used for autosuggestions. The normalization is mostly relevant
for CDPATH=. (the default) but it doesn't hurt others.

Closes #9407
---
 src/path.cpp         | 24 ++++++++++--------------
 tests/checks/cd.fish |  9 +++++++++
 2 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/src/path.cpp b/src/path.cpp
index 40dffcf79..3a5f9772b 100644
--- a/src/path.cpp
+++ b/src/path.cpp
@@ -186,24 +186,20 @@ wcstring_list_t path_apply_cdpath(const wcstring &dir, const wcstring &wd,
         }
         // Always append $PWD
         cdpathsv.push_back(L".");
-        for (wcstring next_path : cdpathsv) {
-            if (next_path.empty()) next_path = L".";
-            if (next_path == L".") {
-                // next_path is just '.', and we have a working directory, so use the wd instead.
-                next_path = wd;
-            }
-
+        for (const wcstring &path : cdpathsv) {
+            wcstring abspath;
             // We want to return an absolute path (see issue 6220)
-            if (string_prefixes_string(L"./", next_path)) {
-                next_path = next_path.replace(0, 2, wd);
-            } else if (string_prefixes_string(L"../", next_path) || next_path == L"..") {
-                next_path = next_path.insert(0, wd);
+            if (path.empty() || (path.front() != L'/' && path.front() != L'~')) {
+                abspath = wd;
+                abspath += L'/';
             }
+            abspath += path;
 
-            expand_tilde(next_path, env_vars);
-            if (next_path.empty()) continue;
+            expand_tilde(abspath, env_vars);
+            if (abspath.empty()) continue;
+            abspath = normalize_path(abspath);
 
-            wcstring whole_path = std::move(next_path);
+            wcstring whole_path = std::move(abspath);
             append_path_component(whole_path, dir);
             paths.push_back(whole_path);
         }
diff --git a/tests/checks/cd.fish b/tests/checks/cd.fish
index 7618d9bcd..3ef82c0fa 100644
--- a/tests/checks/cd.fish
+++ b/tests/checks/cd.fish
@@ -258,3 +258,12 @@ end
 # CHECKERR: ^
 # CHECKERR: in function 'cd' with arguments 'broken-symbolic-link'
 # CHECKERR: called on line {{\d+}} of file {{.*}}/cd.fish
+
+begin
+    mkdir -p foo/bar/muf
+    set -lx CDPATH foo/bar
+    cd muf
+    echo $PWD | grep -q ^/ && echo '$PWD is absolute'
+    # CHECK: $PWD is absolute
+    cd ../../..
+end