From 322ceb7ab4be5b07c3bfa7fc240065916641f8c0 Mon Sep 17 00:00:00 2001
From: Johannes Altmanninger <aclopte@gmail.com>
Date: Thu, 24 Dec 2020 08:53:08 +0100
Subject: [PATCH] builtin realpath: use absolute path also with
 -s/--no-symlinks

The old test needs to be changed because $XDG_DATA_HOME can be relative.

Fixes #7574
---
 src/builtin_realpath.cpp   | 13 ++++++++-----
 tests/checks/realpath.fish | 15 ++++++++++++---
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/builtin_realpath.cpp b/src/builtin_realpath.cpp
index 44739cf3d..1268e4e73 100644
--- a/src/builtin_realpath.cpp
+++ b/src/builtin_realpath.cpp
@@ -12,6 +12,7 @@
 #include "common.h"
 #include "fallback.h"  // IWYU pragma: keep
 #include "io.h"
+#include "wcstringutil.h"
 #include "wgetopt.h"
 #include "wutil.h"  // IWYU pragma: keep
 
@@ -80,25 +81,27 @@ maybe_t<int> builtin_realpath(parser_t &parser, io_streams_t &streams, wchar_t *
         return STATUS_INVALID_ARGS;
     }
 
+    const wchar_t *arg = argv[optind];
+
     if (!opts.no_symlinks) {
-        if (auto real_path = wrealpath(argv[optind])) {
+        if (auto real_path = wrealpath(arg)) {
             streams.out.append(*real_path);
         } else {
             if (errno) {
                 // realpath() just couldn't do it. Report the error and make it clear
                 // this is an error from our builtin, not the system's realpath.
-                streams.err.append_format(L"builtin %ls: %ls: %s\n", cmd, argv[optind],
+                streams.err.append_format(L"builtin %ls: %ls: %s\n", cmd, arg,
                                           std::strerror(errno));
             } else {
                 // Who knows. Probably a bug in our wrealpath() implementation.
-                streams.err.append_format(_(L"builtin %ls: Invalid path: %ls\n"), cmd,
-                                          argv[optind]);
+                streams.err.append_format(_(L"builtin %ls: Invalid arg: %ls\n"), cmd, arg);
             }
 
             return STATUS_CMD_ERROR;
         }
     } else {
-        streams.out.append(normalize_path(argv[optind], /* allow leading double slashes */ false));
+        wcstring absolute_arg = string_prefixes_string(L"/", arg) ? arg : wgetcwd() + L"/" + arg;
+        streams.out.append(normalize_path(absolute_arg, /* allow leading double slashes */ false));
     }
 
     streams.out.append(L"\n");
diff --git a/tests/checks/realpath.fish b/tests/checks/realpath.fish
index 60560865e..8e055c873 100644
--- a/tests/checks/realpath.fish
+++ b/tests/checks/realpath.fish
@@ -63,8 +63,8 @@ else
 end
 
 # With "-s" the symlink is not resolved.
-set -l real_path (builtin realpath -s $XDG_DATA_HOME/fish-symlink)
-set -l expected_real_path "$XDG_DATA_HOME/fish-symlink"
+set -l real_path (builtin realpath -s $data_home_realpath/fish-symlink)
+set -l expected_real_path "$data_home_realpath/fish-symlink"
 if test "$real_path" = "$expected_real_path"
     echo "fish-symlink handled correctly"
     # CHECK: fish-symlink handled correctly
@@ -72,7 +72,16 @@ else
     echo "fish-symlink not handled correctly: $real_path != $expected_real_path" >&2
 end
 
-test (builtin realpath -s /usr/bin/../) = "/usr"
+set -l real_path (builtin realpath -s .)
+set -l expected_real_path (pwd) # Logical working directory.
+if test "$real_path" = "$expected_real_path"
+    echo "relative path correctly handled"
+    # CHECK: relative path correctly handled
+else
+    echo "relative path not handled correctly: $real_path != $expected_real_path" >&2
+end
+
+test (builtin realpath -s /usr/bin/../) = /usr
 or echo builtin realpath -s does not resolve .. or resolves symlink wrong
 
 # A nonexistent file relative to a valid symlink to a directory gets converted.