cp: normalize path when checking for duplicate source

Author: matrixhead

src/uu/cp/src/cp.rs

@@ -29,7 +29,7 @@ use platform::copy_on_write;
 use uucore::display::Quotable;
 use uucore::error::{set_exit_code, UClapError, UError, UResult, UUsageError};
 use uucore::fs::{
-    are_hardlinks_to_same_file, canonicalize, get_filename, is_symlink_loop,
+    are_hardlinks_to_same_file, canonicalize, get_filename, is_symlink_loop, normalize_path,
     path_ends_with_terminator, paths_refer_to_same_file, FileInformation, MissingHandling,
     ResolveMode,
 };
@@ -1264,8 +1264,8 @@ pub fn copy(sources: &[PathBuf], target: &Path, options: &Options) -> CopyResult
     };
 
     for source in sources {
-        if seen_sources.contains(source) {
-            // FIXME: compare sources by the actual file they point to, not their path. (e.g. dir/file == dir/../dir/file in most cases)
+        let normalized_source = normalize_path(source);
+        if seen_sources.contains(&normalized_source) {
             show_warning!("source file {} specified more than once", source.quote());
         } else {
             let dest = construct_dest_path(source, target, target_type, options)
@@ -1309,7 +1309,7 @@ pub fn copy(sources: &[PathBuf], target: &Path, options: &Options) -> CopyResult
                 copied_destinations.insert(dest.clone());
             }
         }
-        seen_sources.insert(source);
+        seen_sources.insert(normalized_source);
     }
 
     if let Some(pb) = progress_bar {

tests/by-util/test_cp.rs

@@ -121,6 +121,19 @@ fn test_cp_duplicate_files() {
     assert_eq!(at.read(TEST_COPY_TO_FOLDER_FILE), "Hello, World!\n");
 }
 
+#[test]
+fn test_cp_duplicate_files_normalized_path() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    ucmd.arg(TEST_HELLO_WORLD_SOURCE)
+        .arg(format!("./{TEST_HELLO_WORLD_SOURCE}"))
+        .arg(TEST_COPY_TO_FOLDER)
+        .succeeds()
+        .stderr_contains(format!(
+            "source file './{TEST_HELLO_WORLD_SOURCE}' specified more than once"
+        ));
+    assert_eq!(at.read(TEST_COPY_TO_FOLDER_FILE), "Hello, World!\n");
+}
+
 #[test]
 fn test_cp_same_file() {
     let (at, mut ucmd) = at_and_ucmd!();