fix(rust): fix overrides on windows and set cwd (#3359)

src/modules/rust.rs

@@ -79,7 +79,7 @@ fn get_module_version(context: &Context, config: &RustConfig) -> Option<String>
         .or_else(|| find_rust_toolchain_file(context))
         .or_else(|| execute_rustup_default(context))
     {
-        match execute_rustup_run_rustc_version(&toolchain) {
+        match execute_rustup_run_rustc_version(context, &toolchain) {
             RustupRunRustcVersionOutcome::RustcVersion(rustc_version) => {
                 format_rustc_version(&rustc_version, config.version_format)
             }
@@ -87,12 +87,12 @@ fn get_module_version(context: &Context, config: &RustConfig) -> Option<String>
             RustupRunRustcVersionOutcome::RustupNotWorking => {
                 // If `rustup` is not in `$PATH` or cannot be executed for other reasons, we can
                 // safely execute `rustc --version`.
-                format_rustc_version(&execute_rustc_version()?, config.version_format)
+                format_rustc_version(&execute_rustc_version(context)?, config.version_format)
             }
             RustupRunRustcVersionOutcome::Err => None,
         }
     } else {
-        format_rustc_version(&execute_rustc_version()?, config.version_format)
+        format_rustc_version(&execute_rustc_version(context)?, config.version_format)
     }
 }
 
@@ -123,15 +123,21 @@ fn extract_toolchain_from_rustup_override_list(stdout: &str, cwd: &Path) -> Opti
     if stdout == "no overrides\n" {
         return None;
     }
+    // use display version of path, also allows stripping \\?\
+    let cwd = cwd.to_string_lossy();
+    // rustup strips \\?\ prefix
+    #[cfg(windows)]
+    let cwd = cwd.strip_prefix(r"\\?\").unwrap_or(&cwd);
+
     stdout
         .lines()
         .filter_map(|line| {
-            let mut words = line.split_whitespace();
-            let dir = words.next()?;
-            let toolchain = words.next()?;
-            Some((dir, toolchain))
+            let (dir, toolchain) = line.split_once('\t')?;
+            Some((dir.trim(), toolchain.trim()))
         })
-        .find(|(dir, _)| cwd.starts_with(dir))
+        // find most specific match
+        .filter(|(dir, _)| cwd.starts_with(dir))
+        .max_by_key(|(dir, _)| dir.len())
         .map(|(_, toolchain)| toolchain.to_owned())
 }
 
@@ -199,9 +205,16 @@ fn find_rust_toolchain_file(context: &Context) -> Option<String> {
     }
 }
 
-fn execute_rustup_run_rustc_version(toolchain: &str) -> RustupRunRustcVersionOutcome {
+fn execute_rustup_run_rustc_version(
+    context: &Context,
+    toolchain: &str,
+) -> RustupRunRustcVersionOutcome {
     create_command("rustup")
-        .and_then(|mut cmd| cmd.args(&["run", toolchain, "rustc", "--version"]).output())
+        .and_then(|mut cmd| {
+            cmd.args(&["run", toolchain, "rustc", "--version"])
+                .current_dir(&context.current_dir)
+                .output()
+        })
         .map(extract_toolchain_from_rustup_run_rustc_version)
         .unwrap_or(RustupRunRustcVersionOutcome::RustupNotWorking)
 }
@@ -222,11 +235,11 @@ fn extract_toolchain_from_rustup_run_rustc_version(output: Output) -> RustupRunR
     RustupRunRustcVersionOutcome::Err
 }
 
-fn execute_rustc_version() -> Option<String> {
-    match create_command("rustc").ok()?.arg("--version").output() {
-        Ok(output) => Some(String::from_utf8(output.stdout).unwrap()),
-        Err(_) => None,
-    }
+fn execute_rustc_version(context: &Context) -> Option<String> {
+    context
+        .exec_cmd("rustc", &["--version"])
+        .map(|o| o.stdout)
+        .filter(|s| !s.is_empty())
 }
 
 fn format_rustc_version(rustc_version: &str, version_format: &str) -> Option<String> {
@@ -275,11 +288,13 @@ mod tests {
         );
 
         static OVERRIDES_INPUT: &str =
-            "/home/user/src/a                                beta-x86_64-unknown-linux-gnu\n\
-             /home/user/src/b                                nightly-x86_64-unknown-linux-gnu\n";
+            "/home/user/src/a                \t                beta-x86_64-unknown-linux-gnu\n\
+             /home/user/src/b                \t                nightly-x86_64-unknown-linux-gnu\n\
+             /home/user/src/b/d c            \t                stable-x86_64-pc-windows-msvc\n";
         static OVERRIDES_CWD_A: &str = "/home/user/src/a/src";
         static OVERRIDES_CWD_B: &str = "/home/user/src/b/tests";
         static OVERRIDES_CWD_C: &str = "/home/user/src/c/examples";
+        static OVERRIDES_CWD_D: &str = "/home/user/src/b/d c/spaces";
         assert_eq!(
             extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_A.as_ref()),
             Some("beta-x86_64-unknown-linux-gnu".to_owned()),
@@ -292,6 +307,29 @@ mod tests {
             extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_C.as_ref()),
             None,
         );
+        assert_eq!(
+            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_D.as_ref()),
+            Some("stable-x86_64-pc-windows-msvc".to_owned()),
+        );
+    }
+
+    #[test]
+    #[cfg(windows)]
+    fn test_extract_toolchain_from_rustup_override_list_win() {
+        static OVERRIDES_INPUT: &str =
+            "C:\\src                \t                beta-x86_64-unknown-linux-gnu\n";
+        static OVERRIDES_CWD_A: &str = r"\\?\C:\src";
+        static OVERRIDES_CWD_B: &str = r"C:\src";
+
+        assert_eq!(
+            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_A.as_ref()),
+            Some("beta-x86_64-unknown-linux-gnu".to_owned()),
+        );
+
+        assert_eq!(
+            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_B.as_ref()),
+            Some("beta-x86_64-unknown-linux-gnu".to_owned()),
+        );
     }
 
     #[cfg(any(unix, windows))]