Use Path::real_parent instead of Path::parent

Except for places where this makes no sense.  Note that real_parent
touches the filesystem and requires the path to exist.

Also, unable to use it in nu-test-support without breaking the test
commands::ucp::copies_the_file_inside_directory_if_path_to_copy_is_directory
which switches cwd out from under its feet (I think).

Cargo.lock

@@ -2794,6 +2794,7 @@ dependencies = [
  "nu-utils",
  "openssl",
  "pretty_assertions",
+ "real_parent",
  "reedline",
  "rstest",
  "serde_json",
@@ -2840,6 +2841,7 @@ dependencies = [
  "nu-utils",
  "once_cell",
  "percent-encoding",
+ "real_parent",
  "reedline",
  "rstest",
  "sysinfo",
@@ -2895,6 +2897,7 @@ dependencies = [
  "nu-parser",
  "nu-protocol",
  "nu-utils",
+ "real_parent",
  "shadow-rs",
 ]
 
@@ -2992,6 +2995,7 @@ dependencies = [
  "quickcheck_macros",
  "rand",
  "rayon",
+ "real_parent",
  "regex",
  "rmp",
  "roxmltree",
@@ -3049,6 +3053,7 @@ dependencies = [
  "nu-path",
  "nu-protocol",
  "nu-utils",
+ "real_parent",
 ]
 
 [[package]]
@@ -3126,6 +3131,7 @@ dependencies = [
  "nu-path",
  "nu-plugin-engine",
  "nu-protocol",
+ "real_parent",
  "rstest",
  "serde_json",
 ]
@@ -3178,6 +3184,7 @@ dependencies = [
  "nu-plugin-protocol",
  "nu-protocol",
  "nu-system",
+ "real_parent",
  "serde",
  "typetag",
  "windows 0.54.0",
@@ -3244,6 +3251,7 @@ dependencies = [
  "num-format",
  "os_pipe",
  "pretty_assertions",
+ "real_parent",
  "rmp-serde",
  "rstest",
  "serde",
@@ -3280,6 +3288,7 @@ dependencies = [
  "ntapi",
  "once_cell",
  "procfs",
+ "real_parent",
  "sysinfo",
  "windows 0.54.0",
 ]
@@ -3374,6 +3383,7 @@ dependencies = [
  "git2",
  "nu-plugin",
  "nu-protocol",
+ "real_parent",
 ]
 
 [[package]]
@@ -4793,6 +4803,12 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "real_parent"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "03ad1715ba6758e16005557a376d29beb8edbfc0a8c272a5412b2044d997ca7f"
+
 [[package]]
 name = "recursive"
 version = "0.1.1"

Cargo.toml

@@ -136,6 +136,7 @@ quote = "1.0"
 rand = "0.8"
 ratatui = "0.26"
 rayon = "1.10"
+real_parent = "0.3.0"
 reedline = "0.32.0"
 regex = "1.9.5"
 rmp = "0.8"
@@ -232,6 +233,7 @@ assert_cmd = "2.0"
 dirs-next = { workspace = true }
 tango-bench = "0.5"
 pretty_assertions = { workspace = true }
+real_parent = { workspace = true }
 rstest = { workspace = true, default-features = false }
 serial_test = "3.1"
 tempfile = { workspace = true }

crates/nu-cli/Cargo.toml

@@ -39,6 +39,7 @@ miette = { workspace = true, features = ["fancy-no-backtrace"] }
 lscolors = { workspace = true, default-features = false, features = ["nu-ansi-term"] }
 once_cell = { workspace = true }
 percent-encoding = { workspace = true }
+real_parent = { workspace = true }
 sysinfo = { workspace = true }
 unicode-segmentation = { workspace = true }
 uuid = { workspace = true, features = ["v4"] }

crates/nu-cli/src/config_files.rs

@@ -9,6 +9,8 @@ use nu_protocol::{
 };
 #[cfg(feature = "plugin")]
 use nu_utils::utils::perf;
+#[cfg(feature = "plugin")]
+use real_parent::PathExt;
 use std::path::PathBuf;
 
 #[cfg(feature = "plugin")]
@@ -180,9 +182,9 @@ pub fn add_plugin_file(
     if let Ok(cwd) = engine_state.cwd_as_string(None) {
         if let Some(plugin_file) = plugin_file {
             let path = Path::new(&plugin_file.item);
-            let path_dir = path.parent().unwrap_or(path);
+            let path_dir = path.real_parent().unwrap_or(path.to_path_buf());
             // Just try to canonicalize the directory of the plugin file first.
-            if let Ok(path_dir) = canonicalize_with(path_dir, &cwd) {
+            if let Ok(path_dir) = canonicalize_with(&path_dir, &cwd) {
                 // Try to canonicalize the actual filename, but it's ok if that fails. The file doesn't
                 // have to exist.
                 let path = path_dir.join(path.file_name().unwrap_or(path.as_os_str()));

crates/nu-cli/src/eval_file.rs

@@ -8,6 +8,7 @@ use nu_protocol::{
     engine::{EngineState, Stack, StateWorkingSet},
     report_error, PipelineData, ShellError, Span, Value,
 };
+use real_parent::PathExt;
 use std::sync::Arc;
 
 /// Entry point for evaluating a file.
@@ -49,9 +50,9 @@ pub fn evaluate_file(
     engine_state.file = Some(file_path.clone());
 
     let parent = file_path
-        .parent()
-        .ok_or_else(|| ShellError::FileNotFoundCustom {
-            msg: format!("The file path '{file_path_str}' does not have a parent"),
+        .real_parent()
+        .map_err(|e| ShellError::FileNotFoundCustom {
+            msg: format!("Cannot determine parent for file path '{file_path_str}': {e}"),
             span: Span::unknown(),
         })?;
 

crates/nu-cmd-lang/Cargo.toml

@@ -18,6 +18,7 @@ nu-protocol = { path = "../nu-protocol", version = "0.95.1" }
 nu-utils = { path = "../nu-utils", version = "0.95.1" }
 
 itertools = { workspace = true }
+real_parent = { workspace = true }
 shadow-rs = { version = "0.29", default-features = false }
 
 [build-dependencies]

crates/nu-cmd-lang/src/core_commands/use_.rs

@@ -5,6 +5,7 @@ use nu_protocol::{
     ast::{Expr, Expression},
     engine::CommandType,
 };
+use real_parent::PathExt;
 
 #[derive(Clone)]
 pub struct Use;
@@ -103,7 +104,7 @@ This command is a parser keyword. For details, check:
                 )?;
                 let maybe_parent = maybe_file_path
                     .as_ref()
-                    .and_then(|path| path.parent().map(|p| p.to_path_buf()));
+                    .and_then(|path| path.real_parent().ok());
 
                 let mut callee_stack = caller_stack
                     .gather_captures(engine_state, &block.captures)

crates/nu-command/Cargo.toml

@@ -72,6 +72,7 @@ print-positions = { workspace = true }
 quick-xml = { workspace = true }
 rand = { workspace = true }
 rayon = { workspace = true }
+real_parent = { workspace = true }
 regex = { workspace = true }
 roxmltree = { workspace = true }
 rusqlite = { workspace = true, features = ["bundled", "backup", "chrono"], optional = true }

crates/nu-command/src/debug/info.rs

@@ -1,4 +1,5 @@
 use nu_engine::command_prelude::*;
+use real_parent::PathExt;
 use sysinfo::{MemoryRefreshKind, Pid, ProcessRefreshKind, RefreshKind, System};
 
 const ENV_PATH_SEPARATOR_CHAR: char = {
@@ -80,7 +81,7 @@ fn all_columns(span: Span) -> Value {
     );
 
     let process = if let Some(p) = sys.process(pid) {
-        let root = if let Some(path) = p.exe().and_then(|p| p.parent()) {
+        let root = if let Some(path) = p.exe().and_then(|p| p.real_parent().ok()) {
             Value::string(path.to_string_lossy().to_string(), span)
         } else {
             Value::nothing(span)

crates/nu-command/src/env/source_env.rs

@@ -3,6 +3,7 @@ use nu_engine::{
     redirect_env,
 };
 use nu_protocol::engine::CommandType;
+use real_parent::PathExt;
 use std::path::PathBuf;
 
 /// Source a file for environment variables.
@@ -66,7 +67,7 @@ impl Command for SourceEnv {
             });
         };
 
-        if let Some(parent) = file_path.parent() {
+        if let Ok(parent) = file_path.real_parent() {
             let file_pwd = Value::string(parent.to_string_lossy(), call.head);
 
             caller_stack.add_env_var("FILE_PWD".to_string(), file_pwd);

crates/nu-engine/Cargo.toml

@@ -15,6 +15,7 @@ nu-protocol = { path = "../nu-protocol", features = ["plugin"], version = "0.95.
 nu-path = { path = "../nu-path", version = "0.95.1" }
 nu-glob = { path = "../nu-glob", version = "0.95.1" }
 nu-utils = { path = "../nu-utils", version = "0.95.1" }
+real_parent = { workspace = true }
 
 [features]
 plugin = []

crates/nu-engine/src/glob_from.rs

@@ -1,6 +1,7 @@
 use nu_glob::MatchOptions;
 use nu_path::{canonicalize_with, expand_path_with};
 use nu_protocol::{NuGlob, ShellError, Span, Spanned};
+use real_parent::PathExt;
 use std::{
     fs,
     path::{Component, Path, PathBuf},
@@ -87,7 +88,7 @@ pub fn glob_from(
                     span: pattern.span,
                 });
             };
-            (path.parent().map(|parent| parent.to_path_buf()), path)
+            (path.real_parent().ok(), path)
         }
     };
 

crates/nu-parser/Cargo.toml

@@ -21,6 +21,7 @@ bytesize = { workspace = true }
 chrono = { default-features = false, features = ['std'], workspace = true }
 itertools = { workspace = true }
 log = { workspace = true }
+real_parent = { workspace = true }
 serde_json = { workspace = true }
 
 [dev-dependencies]

crates/nu-plugin-engine/Cargo.toml

@@ -17,6 +17,7 @@ nu-system = { path = "../nu-system", version = "0.95.1" }
 nu-plugin-protocol = { path = "../nu-plugin-protocol", version = "0.95.1" }
 nu-plugin-core = { path = "../nu-plugin-core", version = "0.95.1", default-features = false }
 
+real_parent = { workspace = true }
 serde = { workspace = true }
 log = { workspace = true }
 

crates/nu-plugin-engine/src/init.rs

@@ -1,3 +1,4 @@
+use real_parent::PathExt;
 use std::{
     io::{BufReader, BufWriter},
     path::Path,
@@ -92,8 +93,8 @@ pub fn create_command(
 
     // In order to make bugs with improper use of filesystem without getting the engine current
     // directory more obvious, the plugin always starts in the directory of its executable
-    if let Some(dirname) = path.parent() {
-        process.current_dir(dirname);
+    if let Ok(dirname) = path.real_parent() {
+        process.current_dir(&dirname);
     }
 
     process

crates/nu-protocol/Cargo.toml

@@ -28,6 +28,7 @@ indexmap = { workspace = true }
 lru = { workspace = true }
 miette = { workspace = true, features = ["fancy-no-backtrace"] }
 num-format = { workspace = true }
+real_parent = { workspace = true }
 rmp-serde = { workspace = true, optional = true }
 serde = { workspace = true, default-features = false }
 thiserror = "1.0"

crates/nu-protocol/src/parser_path.rs

@@ -1,4 +1,5 @@
 use crate::engine::{StateWorkingSet, VirtualPath};
+use real_parent::PathExt;
 use std::{
     ffi::OsStr,
     path::{Path, PathBuf},
@@ -57,11 +58,11 @@ impl ParserPath {
         }
     }
 
-    pub fn parent(&self) -> Option<&Path> {
+    pub fn parent(&self) -> Option<PathBuf> {
         match self {
-            ParserPath::RealPath(p) => p.parent(),
-            ParserPath::VirtualFile(p, _) => p.parent(),
-            ParserPath::VirtualDir(p, _) => p.parent(),
+            ParserPath::RealPath(p) => p.real_parent().ok(),
+            ParserPath::VirtualFile(p, _) => p.parent().map(|p| p.to_path_buf()),
+            ParserPath::VirtualDir(p, _) => p.parent().map(|p| p.to_path_buf()),
         }
     }
 

crates/nu-system/Cargo.toml

@@ -27,6 +27,7 @@ procfs = { workspace = true }
 [target.'cfg(target_os = "macos")'.dependencies]
 libproc = { workspace = true }
 mach2 = { workspace = true }
+real_parent = { workspace = true }
 
 [target.'cfg(target_os = "windows")'.dependencies]
 chrono = { workspace = true, default-features = false, features = ["clock"] }

crates/nu-system/src/macos.rs

@@ -8,6 +8,7 @@ use libproc::libproc::task_info::{TaskAllInfo, TaskInfo};
 use libproc::libproc::thread_info::ThreadInfo;
 use libproc::processes::{pids_by_type, ProcFilter};
 use mach2::mach_time;
+use real_parent::PathExt;
 use std::cmp;
 use std::path::{Path, PathBuf};
 use std::thread;
@@ -190,8 +191,8 @@ fn get_path_info(pid: i32, mut size: size_t) -> Option<PathInfo> {
                 let mut need_root = true;
                 let mut root = Default::default();
                 if exe.is_absolute() {
-                    if let Some(parent) = exe.parent() {
-                        root = parent.to_path_buf();
+                    if let Ok(parent) = exe.real_parent() {
+                        root = parent;
                         need_root = false;
                     }
                 }

crates/nu-test-support/src/macros.rs

@@ -349,8 +349,10 @@ where
         temp_file
     });
 
-    // We don't have to write the plugin registry file, it's ok for it to not exist
+    // We have to write the plugin registry file, it must exist now we're using real_parent
     let temp_plugin_file = temp.path().join("plugin.msgpackz");
+    std::fs::File::create(&temp_plugin_file)
+        .expect("couldn't create temporary plugin registry file");
 
     crate::commands::ensure_plugins_built();
 

crates/nu_plugin_gstat/Cargo.toml

@@ -18,5 +18,6 @@ bench = false
 [dependencies]
 nu-plugin = { path = "../nu-plugin", version = "0.95.1" }
 nu-protocol = { path = "../nu-protocol", version = "0.95.1" }
+real_parent = { workspace = true }
 
 git2 = "0.19"

crates/nu_plugin_gstat/src/gstat.rs

@@ -1,5 +1,6 @@
 use git2::{Branch, BranchType, DescribeOptions, Repository};
 use nu_protocol::{record, IntoSpanned, LabeledError, Span, Spanned, Value};
+use real_parent::PathExt;
 use std::{fmt::Write, ops::BitAnd, path::Path};
 
 // git status
@@ -91,8 +92,9 @@ impl GStat {
 
         let repo_name = repo
             .path()
-            .parent()
-            .and_then(|p| p.file_name())
+            .real_parent()
+            .map_err(|e| LabeledError::new(e.to_string()))?
+            .file_name()
             .map(|p| p.to_string_lossy().to_string())
             .unwrap_or_else(|| "".to_string());
 

tests/plugins/registry_file.rs

@@ -1,3 +1,4 @@
+use real_parent::PathExt;
 use std::{fs::File, path::PathBuf};
 
 use nu_protocol::{PluginRegistryFile, PluginRegistryItem, PluginRegistryItemData};
@@ -49,7 +50,7 @@ fn plugin_add_then_restart_nu() {
 fn plugin_add_in_nu_plugin_dirs_const() {
     let example_plugin_path = example_plugin_path();
 
-    let dirname = example_plugin_path.parent().expect("no parent");
+    let dirname = example_plugin_path.real_parent().expect("no parent");
     let filename = example_plugin_path
         .file_name()
         .expect("no file_name")
@@ -84,7 +85,7 @@ fn plugin_add_in_nu_plugin_dirs_const() {
 fn plugin_add_in_nu_plugin_dirs_env() {
     let example_plugin_path = example_plugin_path();
 
-    let dirname = example_plugin_path.parent().expect("no parent");
+    let dirname = example_plugin_path.real_parent().expect("no parent");
     let filename = example_plugin_path
         .file_name()
         .expect("no file_name")