fix(Import): case-fold media filenames when checking uniqueness (#4435)

* add wrapper struct with case-folding get impl

* use wrapper struct

* restrict case-folding to windows

* Revert "restrict case-folding to windows"

This reverts commit aad01d904f.

* case-fold filenames for newly added media

* add test

* fix incorrect comment

rslib/src/import_export/package/apkg/import/media.rs

@@ -17,6 +17,7 @@ use crate::import_export::package::media::SafeMediaEntry;
 use crate::import_export::ImportProgress;
 use crate::media::files::add_hash_suffix_to_file_stem;
 use crate::media::files::sha1_of_reader;
+use crate::media::Checksums;
 use crate::prelude::*;
 use crate::progress::ThrottlingProgressHandler;
 
@@ -75,7 +76,7 @@ impl Context<'_> {
 fn prepare_media(
     media_entries: Vec<SafeMediaEntry>,
     archive: &mut ZipArchive<File>,
-    existing_sha1s: &HashMap<String, Sha1Hash>,
+    existing_sha1s: &Checksums,
     progress: &mut ThrottlingProgressHandler<ImportProgress>,
 ) -> Result<MediaUseMap> {
     let mut media_map = MediaUseMap::default();

rslib/src/media/files.rs

@@ -173,7 +173,9 @@ pub fn add_data_to_folder_uniquely<'a, P>(
 where
     P: AsRef<Path>,
 {
-    let normalized_name = normalize_filename(desired_name);
+    // force lowercase to account for case-insensitive filesystems
+    // but not within normalize_filename, for existing media refs
+    let normalized_name: Cow<_> = normalize_filename(desired_name).to_lowercase().into();
 
     let mut target_path = folder.as_ref().join(normalized_name.as_ref());
 
@@ -496,8 +498,14 @@ mod test {
             "test.mp3"
         );
 
-        // different contents
+        // different contents, filenames differ only by case
         let h2 = sha1_of_data(b"hello1");
+        assert_eq!(
+            add_data_to_folder_uniquely(dpath, "Test.mp3", b"hello1", h2).unwrap(),
+            "test-88fdd585121a4ccb3d1540527aee53a77c77abb8.mp3"
+        );
+
+        // same contents, filenames differ only by case
         assert_eq!(
             add_data_to_folder_uniquely(dpath, "test.mp3", b"hello1", h2).unwrap(),
             "test-88fdd585121a4ccb3d1540527aee53a77c77abb8.mp3"

rslib/src/media/mod.rs

@@ -6,7 +6,6 @@ pub mod files;
 mod service;
 
 use std::borrow::Cow;
-use std::collections::HashMap;
 use std::path::Path;
 use std::path::PathBuf;
 
@@ -22,6 +21,7 @@ use crate::progress::ThrottlingProgressHandler;
 use crate::sync::http_client::HttpSyncClient;
 use crate::sync::login::SyncAuth;
 use crate::sync::media::database::client::changetracker::ChangeTracker;
+pub use crate::sync::media::database::client::Checksums;
 use crate::sync::media::database::client::MediaDatabase;
 use crate::sync::media::database::client::MediaEntry;
 use crate::sync::media::progress::MediaSyncProgress;
@@ -157,7 +157,7 @@ impl MediaManager {
     pub fn all_checksums_after_checking(
         &self,
         progress: impl FnMut(usize) -> bool,
-    ) -> Result<HashMap<String, Sha1Hash>> {
+    ) -> Result<Checksums> {
         ChangeTracker::new(&self.media_folder, progress).register_changes(&self.db)?;
         self.db.all_registered_checksums()
     }
@@ -176,7 +176,7 @@ impl MediaManager {
 
     /// All checksums without registering changes first.
     #[cfg(test)]
-    pub(crate) fn all_checksums_as_is(&self) -> HashMap<String, [u8; 20]> {
+    pub(crate) fn all_checksums_as_is(&self) -> Checksums {
         self.db.all_registered_checksums().unwrap()
     }
 }

rslib/src/sync/media/database/client/mod.rs

@@ -18,6 +18,20 @@ use crate::prelude::*;
 
 pub mod changetracker;
 
+pub struct Checksums(HashMap<String, Sha1Hash>);
+
+impl Checksums {
+    // case-fold filenames when checking files to be imported
+    // to account for case-insensitive filesystems
+    pub fn get(&self, key: impl AsRef<str>) -> Option<&Sha1Hash> {
+        self.0.get(key.as_ref().to_lowercase().as_str())
+    }
+
+    pub fn contains_key(&self, key: impl AsRef<str>) -> bool {
+        self.get(key).is_some()
+    }
+}
+
 #[derive(Debug, PartialEq, Eq)]
 pub struct MediaEntry {
     pub fname: String,
@@ -175,11 +189,12 @@ delete from media where fname=?",
     }
 
     /// Returns all filenames and checksums, where the checksum is not null.
-    pub(crate) fn all_registered_checksums(&self) -> error::Result<HashMap<String, Sha1Hash>> {
+    pub(crate) fn all_registered_checksums(&self) -> error::Result<Checksums> {
         self.db
             .prepare("SELECT fname, csum FROM media WHERE csum IS NOT NULL")?
             .query_and_then([], row_to_name_and_checksum)?
-            .collect()
+            .collect::<error::Result<_>>()
+            .map(Checksums)
     }
 
     pub(crate) fn force_resync(&self) -> error::Result<()> {