ElyMark: dropped and pasted pictures copy into assets and link at the caret (C14.10)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

crates/ely-files/src/lib.rs

@@ -19,6 +19,7 @@ pub use task::RecoveryTask;
 
 pub use save::{
     SaveError, Saved, atomic_capable, claim_all, export, import_attachment, same_file, save,
+    write_attachment,
     save_as, save_atomic, save_overwrite, save_with_backup, save_with_probe,
 };
 pub use session::{Fingerprint, Open, SaveState, SaveTicket, Session, Sessions, StaleTicket};

crates/ely-files/src/save.rs

@@ -212,24 +212,38 @@ pub fn same_file(a: &Path, b: &Path) -> io::Result<bool> {
 
 /// Copies an attachment in; the source is never touched (FILE-07).
 pub fn import_attachment(source: &Path, dir: &Path) -> io::Result<PathBuf> {
-    std::fs::create_dir_all(dir).map_err(|e| with_path(dir, e))?;
     let name = source.file_name().ok_or_else(|| {
         io::Error::new(
             io::ErrorKind::InvalidInput,
             format!("{} has no file name", source.display()),
         )
     })?;
-    let mut target = dir.join(name);
-    let stem = Path::new(name)
-        .file_stem()
-        .unwrap_or_default()
-        .to_string_lossy()
-        .into_owned();
-    let ext = Path::new(name)
+    let mut from = std::fs::File::open(source).map_err(|e| with_path(source, e))?;
+    let target = attach(dir, Path::new(name), |to| io::copy(&mut from, to).map(drop))?;
+    log::info!("files: imported {} to {}", source.display(), target.display());
+    Ok(target)
+}
+
+/// Writes `bytes` into `dir` as `name`, or a free variant.
+pub fn write_attachment(name: &str, bytes: &[u8], dir: &Path) -> io::Result<PathBuf> {
+    let target = attach(dir, Path::new(name), |to| to.write_all(bytes))?;
+    log::info!("files: wrote {} bytes to {}", bytes.len(), target.display());
+    Ok(target)
+}
+
+/// Claims a free name like `name`, then fills it.
+fn attach(
+    dir: &Path,
+    name: &Path,
+    fill: impl FnOnce(&mut std::fs::File) -> io::Result<()>,
+) -> io::Result<PathBuf> {
+    std::fs::create_dir_all(dir).map_err(|e| with_path(dir, e))?;
+    let stem = name.file_stem().unwrap_or_default().to_string_lossy().into_owned();
+    let ext = name
         .extension()
         .map(|ext| ext.to_string_lossy().into_owned())
         .unwrap_or_default();
-    let mut from = std::fs::File::open(source).map_err(|e| with_path(source, e))?;
+    let mut target = dir.join(name);
     let mut counter = 1;
     // Claims the name; another writer's file is never replaced.
     let mut to = loop {
@@ -242,17 +256,12 @@ pub fn import_attachment(source: &Path, dir: &Path) -> io::Result<PathBuf> {
             Err(e) => return Err(with_path(&target, e)),
         }
     };
-    let copied = io::copy(&mut from, &mut to).and_then(|_| to.flush());
-    if let Err(e) = copied {
+    let filled = fill(&mut to).and_then(|()| to.flush());
+    if let Err(e) = filled {
         // A half copy is not left behind.
         std::fs::remove_file(&target).ok();
         return Err(with_path(&target, e));
     }
-    log::info!(
-        "files: imported {} to {}",
-        source.display(),
-        target.display()
-    );
     Ok(target)
 }
 

crates/ely-files/src/save/tests.rs

@@ -180,6 +180,15 @@ fn an_import_copies_and_never_deletes() {
     assert_eq!(read(&second), "png-bytes");
 }
 
+#[test]
+fn written_bytes_take_a_free_name() {
+    let dir = tempfile::tempdir().expect("a temp dir");
+    let first = write_attachment("pasted.png", b"one", dir.path()).expect("the first write");
+    let second = write_attachment("pasted.png", b"two", dir.path()).expect("the second write");
+    assert_ne!(first, second);
+    assert_eq!((read(&first), read(&second)), ("one".into(), "two".into()));
+}
+
 #[test]
 fn a_numbered_import_name_fits_long_file_names() {
     let dir = tempfile::tempdir().expect("a temp dir");