Convert paths to absolute before normalization (#1489)

* Add test

* Fix test

* Convert paths to absolute before normalization

The path normalization function doesn't work on paths starting with '..'.
One fix is to make paths absolute.

* Add comment

.gitignore

@@ -27,3 +27,6 @@
 # Python virtual env
 .venv/
 venv/
+
+# helix configuration
+.helix/

core/src/cache.rs

@@ -289,7 +289,7 @@ impl Cache {
     pub fn add_file(&mut self, path: impl Into<OsString>) -> io::Result<FileId> {
         let path = path.into();
         let timestamp = timestamp(&path)?;
-        let normalized = normalize_path(PathBuf::from(&path).as_path());
+        let normalized = normalize_path(&path)?;
         self.add_file_(normalized, timestamp)
     }
 
@@ -298,7 +298,7 @@ impl Cache {
     /// If it was not in cache, try to read it from the filesystem and add it as a new entry.
     pub fn get_or_add_file(&mut self, path: impl Into<OsString>) -> io::Result<CacheOp<FileId>> {
         let path = path.into();
-        let normalized = normalize_path(PathBuf::from(&path).as_path());
+        let normalized = normalize_path(&path)?;
         match self.id_or_new_timestamp_of(&path)? {
             SourceState::UpToDate(id) => Ok(CacheOp::Cached(id)),
             SourceState::Stale(timestamp) => {
@@ -1241,7 +1241,18 @@ fn with_parent(path: &OsStr, parent: Option<PathBuf>) -> PathBuf {
 
 /// Normalize the path of a file for unique identification in the cache.
 ///
-/// This implementation (including the commend below) was taken from cargo-util.
+/// The returned path will be an absolute path.
+pub fn normalize_path(path: &OsStr) -> std::io::Result<OsString> {
+    let mut path = PathBuf::from(path);
+    if path.is_relative() {
+        path = std::env::current_dir()?.join(path);
+    }
+    Ok(normalize_abs_path(&path))
+}
+
+/// Normalize the path (assumed to be absolute) of a file for unique identification in the cache.
+///
+/// This implementation (including the comment below) was taken from cargo-util.
 ///
 /// CAUTION: This does not resolve symlinks (unlike
 /// [`std::fs::canonicalize`]). This may cause incorrect or surprising
@@ -1249,7 +1260,7 @@ fn with_parent(path: &OsStr, parent: Option<PathBuf>) -> PathBuf {
 /// [`std::fs::canonicalize`] can be hard to use correctly, since it can often
 /// fail, or on Windows returns annoying device paths. This is a problem Cargo
 /// needs to improve on.
-pub fn normalize_path(path: &Path) -> OsString {
+fn normalize_abs_path(path: &Path) -> OsString {
     use std::path::Component;
 
     let mut components = path.components().peekable();

core/tests/integration/imports/imported/import_parent.ncl

@@ -0,0 +1,2 @@
+# test.type = 'pass'
+import "../root_path.ncl"

core/tests/integration/main.rs

@@ -37,6 +37,25 @@ fn check_annotated_nickel_file(path: &str) {
         .expect("Failed to join thread")
 }
 
+// Like check_annotated_nickel_file, but runs the test from the directory of
+// the test file itself (and opens the test file with a relative path). This
+// is mainly for integration testing path normalization.
+#[test_resources("core/tests/integration/imports/imported/import_parent.ncl")]
+fn check_from_dir(path: &str) {
+    let test: TestCase<Test> =
+        read_annotated_test_case(path).expect("Failed to parse annotated program");
+
+    let path = project_root().join(path);
+    let dir = std::env::current_dir().unwrap();
+    let test_dir = path.parent().unwrap();
+    std::env::set_current_dir(test_dir).unwrap();
+    run_test(
+        test,
+        String::from(path.file_name().unwrap().to_string_lossy()),
+    );
+    std::env::set_current_dir(dir).unwrap();
+}
+
 fn run_test(test_case: TestCase<Test>, path: String) {
     let repeat = test_case.annotation.repeat.unwrap_or(1);
     let eval_strategy = test_case.annotation.eval.unwrap_or(EvalStrategy::Standard);