From 5cce6d01add5fbe2c3293f6d1da44d0348a46e47 Mon Sep 17 00:00:00 2001
From: Fabian Homborg <FHomborg@gmail.com>
Date: Thu, 7 Apr 2022 15:13:10 +0200
Subject: [PATCH] resolve: Normalize

This means "../" components are cancelled out even after non-existent
paths or files.

(the alternative is to error out, but being able to say `path resolve
/path/to/file/../../` over `path resolve (path dirname
/path/to/file)/../../` seems worth it?)
---
 src/builtins/path.cpp  | 5 +++++
 tests/checks/path.fish | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/src/builtins/path.cpp b/src/builtins/path.cpp
index b1840d9fd..fca03bd82 100644
--- a/src/builtins/path.cpp
+++ b/src/builtins/path.cpp
@@ -675,6 +675,11 @@ static int path_resolve(parser_t &parser, io_streams_t &streams, int argc, const
             }
         }
 
+        // Normalize the path so "../" components are eliminated even after
+        // nonexistent or non-directory components.
+        // Otherwise `path resolve foo/../` will be `$PWD/foo/../` if foo is a file.
+        real = normalize_path(*real, false);
+
         // Return 0 if we found a realpath.
         if (opts.quiet) {
             return STATUS_CMD_OK;
diff --git a/tests/checks/path.fish b/tests/checks/path.fish
index ae14e5022..7334f0e7d 100644
--- a/tests/checks/path.fish
+++ b/tests/checks/path.fish
@@ -118,6 +118,10 @@ path resolve bin//sh | string match -r -- 'bin/bash$'
 # sh here is bash
 # CHECK: bin/bash
 
+# "../" cancels out even files.
+path resolve bin//sh/../ | string match -r -- 'bin$'
+# CHECK: bin
+
 # `path resolve` with nonexistent paths
 set -l path (path resolve foo/bar)
 string match -rq "^"(pwd -P | string escape --style=regex)'/' -- $path