Open Save As and export dialogs in the document's own folder (#4012)

* Save As and exports open in the document's own folder

Save As, saving a document that needs a location, the Office and
comment/form data exports, Optimize and Sign now start the file dialog in
the folder of the open PDF instead of the system's default. A new
document and an email attachment's temporary copy keep the old behaviour.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Match the full Outlook temporary-copy layout before skipping the document folder

Anchor is_mail_temp_copy to the cache layout (one random folder, then the file) and
to the Packages\Microsoft.OutlookForWindows_<id> folder, so ordinary paths that merely
contain those names keep the document's own folder. Regression cases added.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/create_ui.rs

@@ -243,6 +243,8 @@ impl PdfCraftApp {
     ) {
         let Some(doc) = self.session.get(id) else { return };
         let (before, name) = (doc.bytes.len(), format!("{} ({}).pdf", stem(&doc.name), kind.suffix()));
+        #[cfg(not(target_arch = "wasm32"))]
+        let folder = doc.path.clone();
         let (bytes, detail) = match result {
             Ok(r) => r,
             Err(e) => {
@@ -284,6 +286,7 @@ impl PdfCraftApp {
                 Some(p) => write(self, p),
                 None => {
                     let dialog = rfd::AsyncFileDialog::new().add_filter("PDF", &["pdf"]).set_file_name(&name);
+                    let dialog = crate::editing::in_document_folder(dialog, folder.as_deref());
                     self.ask_one(crate::pickers::Ask::Save(dialog), None, move |app, p| write(app, p.to_string_lossy().into_owned()));
                 }
             }

crates/ui-egui/src/editing.rs

@@ -637,6 +637,7 @@ impl PdfCraftApp {
         let (name, path) = (doc.name.clone(), doc.path.clone());
         #[cfg(not(target_arch = "wasm32"))]
         {
+            let doc_path = path.clone();
             let destination = match (target, path, &self.save_override) {
                 (_, _, Some(p)) => p.clone(),
                 // An email attachment's temporary copy is no place to keep work: ask, as for a new
@@ -645,6 +646,7 @@ impl PdfCraftApp {
                 _ => {
                     let name = if name.to_ascii_lowercase().ends_with(".pdf") { name } else { format!("{name}.pdf") };
                     let dialog = rfd::AsyncFileDialog::new().add_filter("PDF", &["pdf"]).set_file_name(name);
+                    let dialog = in_document_folder(dialog, doc_path.as_deref());
                     // The bytes are taken once the user has chosen, so edits made meanwhile are saved too.
                     self.ask_one(crate::pickers::Ask::Save(dialog), None, move |app, dest| {
                         app.save_doc_to_then(id, &dest.to_string_lossy(), target, Box::new(after));
@@ -1019,19 +1021,44 @@ fn is_form_edit(edit: &Edit) -> bool {
 ///
 /// Outlook opens an attachment from its own cache: `INetCache\Content.Outlook\<random>\` for
 /// classic Outlook (`Temporary Internet Files\Content.Outlook\` on older Windows), and the
-/// `Microsoft.OutlookForWindows` package folder for the new Outlook. Saving there either fails,
+/// `Packages\Microsoft.OutlookForWindows_<id>` package folder for the new Outlook. The patterns
+/// follow those layouts, so an ordinary folder that merely shares a name doesn't match. Saving there either fails,
 /// because Outlook can still hold the file, or appears to work while the edits stay out of the
 /// email and are deleted with the cache. Apple Mail opens one from `Mail Downloads/<UUID>/` in
 /// its sandbox container, where other apps can't write, so saving there fails (#2751). Matched on
 /// either separator and in any case, so it can be tested on every platform.
 pub(crate) fn is_mail_temp_copy(path: &str) -> bool {
     let p = path.replace('\\', "/").to_ascii_lowercase();
-    p.contains("/inetcache/content.outlook/")
-        || p.contains("/temporary internet files/content.outlook/")
-        || p.contains("/microsoft.outlookforwindows")
+    // Outlook's cache holds `<marker><random folder>/<file>`: exactly one folder, then the file.
+    let in_outlook_cache = |marker: &str| {
+        p.split_once(marker)
+            .is_some_and(|(_, rest)| matches!(rest.split('/').collect::<Vec<_>>()[..], [dir, file] if !dir.is_empty() && !file.is_empty()))
+    };
+    in_outlook_cache("/inetcache/content.outlook/")
+        || in_outlook_cache("/temporary internet files/content.outlook/")
+        || p.contains("/packages/microsoft.outlookforwindows_")
         || p.contains("/library/containers/com.apple.mail/data/library/mail downloads/")
 }
 
+/// The folder a Save As style dialog should open in for a document stored at `path`: the
+/// document's own folder, as Acrobat and Foxit do, instead of whichever folder the system picks.
+/// `None` (keep the system's choice) for a new document, a path with no parent, or an email
+/// attachment's temporary copy (`is_mail_temp_copy`), which is no place to keep work. Also right
+/// for UNC paths on Windows (`\\server\share\dir\f.pdf` gives `\\server\share\dir`).
+pub(crate) fn save_dialog_folder(path: Option<&str>) -> Option<std::path::PathBuf> {
+    let path = path.filter(|p| !is_mail_temp_copy(p))?;
+    let parent = std::path::Path::new(path).parent()?;
+    (!parent.as_os_str().is_empty()).then(|| parent.to_path_buf())
+}
+
+/// `dialog` opened in the folder of the document stored at `path` ([`save_dialog_folder`]).
+pub(crate) fn in_document_folder(dialog: rfd::AsyncFileDialog, path: Option<&str>) -> rfd::AsyncFileDialog {
+    match save_dialog_folder(path) {
+        Some(dir) => dialog.set_directory(dir),
+        None => dialog,
+    }
+}
+
 /// Write via a temporary file in the same directory and rename over the target, so a crash or
 /// full disk never leaves a half-written PDF where the original was.
 pub fn write_atomically(path: &str, bytes: &[u8]) -> std::io::Result<()> {
@@ -1146,7 +1173,31 @@ fn bookmark_at<'a>(items: &'a [pdfcraft_render::OutlineItem], path: &[usize]) ->
 
 #[cfg(test)]
 mod tests {
-    use super::{SaveTarget, is_mail_temp_copy, write_atomically, write_atomically_syncing, write_atomically_with};
+    use super::{SaveTarget, is_mail_temp_copy, save_dialog_folder, write_atomically, write_atomically_syncing, write_atomically_with};
+
+    #[test]
+    fn save_dialogs_open_in_the_documents_folder() {
+        use std::path::PathBuf;
+        assert_eq!(save_dialog_folder(Some("/home/a/plans/f.pdf")), Some(PathBuf::from("/home/a/plans")));
+        // A new document has no folder yet; a bare name has an empty parent; the root has none.
+        assert_eq!(save_dialog_folder(None), None);
+        assert_eq!(save_dialog_folder(Some("f.pdf")), None);
+        assert_eq!(save_dialog_folder(Some("/")), None);
+        // An email attachment's temporary copy is not offered.
+        assert_eq!(save_dialog_folder(Some("C:\\Users\\a\\AppData\\Local\\Microsoft\\Windows\\INetCache\\Content.Outlook\\AB12\\f.pdf")), None);
+        assert_eq!(save_dialog_folder(Some("/Users/a/Library/Containers/com.apple.mail/Data/Library/Mail Downloads/UUID/f.pdf")), None);
+    }
+
+    /// The Windows rules for `Path::parent` (UNC share roots included) only apply on Windows.
+    #[cfg(windows)]
+    #[test]
+    fn save_dialog_folder_handles_unc_paths() {
+        use std::path::PathBuf;
+        assert_eq!(save_dialog_folder(Some(r"\\nas\projets\2026\f.pdf")), Some(PathBuf::from(r"\\nas\projets\2026")));
+        assert_eq!(save_dialog_folder(Some(r"\\nas\projets\f.pdf")), Some(PathBuf::from(r"\\nas\projets\")));
+        assert_eq!(save_dialog_folder(Some(r"\\nas\projets")), None);
+        assert_eq!(save_dialog_folder(Some(r"C:\Users\a\f.pdf")), Some(PathBuf::from(r"C:\Users\a")));
+    }
     use pdfcraft_platform::staging::{STAGING_ATTEMPTS, staging_suffixes};
     use std::path::{Path, PathBuf};
 
@@ -1389,6 +1440,9 @@ mod tests {
             r"C:\Users\me\Documents\Quote.pdf",
             r"C:\Users\me\OneDrive - Contoso\Content.Outlook notes\Quote.pdf",
             r"C:\Users\me\AppData\Local\Microsoft\Windows\INetCache\IE\Quote.pdf",
+            "/home/microsoft.outlookforwindows/report.pdf",
+            "/x/inetcache/content.outlook/y.pdf",
+            "/x/temporary internet files/content.outlook/y.pdf",
             "/home/me/Documents/Quote.pdf",
             "/Users/me/Downloads/Mail Downloads/booking.pdf",
             "/Users/me/Library/Containers/com.apple.Notes/Data/Library/Mail Downloads/booking.pdf",

crates/ui-egui/src/files.rs

@@ -875,6 +875,7 @@ impl PdfCraftApp {
         let Some(doc) = self.session.get(id) else { return };
         let stem = doc.name.trim_end_matches(".pdf").trim_end_matches(".PDF").to_string();
         let ext = format.extension();
+        let folder = doc.path.clone();
         let bytes = doc.export_office(format);
         #[cfg(not(target_arch = "wasm32"))]
         {
@@ -889,6 +890,7 @@ impl PdfCraftApp {
                         .set_title(tl!("Export").to_string())
                         .add_filter(ext.to_uppercase(), &[ext])
                         .set_file_name(format!("{stem}.{ext}"));
+                    let dialog = crate::editing::in_document_folder(dialog, folder.as_deref());
                     self.ask_one(crate::pickers::Ask::Save(dialog), None, write);
                 }
             }
@@ -971,6 +973,7 @@ impl PdfCraftApp {
         let stem = doc.name.trim_end_matches(".pdf").trim_end_matches(".PDF").to_string();
         #[cfg(not(target_arch = "wasm32"))]
         {
+            let folder = doc.path.clone();
             let xfa = doc.info.xfa.is_some();
             let write = move |app: &mut Self, path: std::path::PathBuf| {
                 // Include what was typed while the save panel was open (#166).
@@ -1010,6 +1013,7 @@ impl PdfCraftApp {
                             .add_filter("CSV", &["csv"])
                             .add_filter(tl!("Text").to_string(), &["txt"])
                     };
+                    let d = crate::editing::in_document_folder(d, folder.as_deref());
                     self.ask_one(crate::pickers::Ask::Save(d), None, write);
                 }
             }

crates/ui-egui/src/sign_ui.rs

@@ -450,6 +450,8 @@ impl PdfCraftApp {
         // Signing saves, as in Acrobat: choose where (a cancelled save cancels signing). The
         // document is signed once the user has chosen.
         let name = self.session.get(doc_id).map(|d| d.name.clone()).unwrap_or_default();
+        #[cfg(not(target_arch = "wasm32"))]
+        let folder = self.session.get(doc_id).and_then(|d| d.path.clone());
         let stem = name.trim_end_matches(".pdf").trim_end_matches(".PDF").to_string();
         let sign_and_save = move |app: &mut Self, path: PathBuf| -> Result<(), String> {
             // Sign what was typed while the save panel was open, too (#166); a refused value
@@ -478,6 +480,7 @@ impl PdfCraftApp {
             #[cfg(not(target_arch = "wasm32"))]
             None => {
                 let dialog = rfd::AsyncFileDialog::new().add_filter("PDF", &["pdf"]).set_file_name(format!("{stem}_signed.pdf"));
+                let dialog = crate::editing::in_document_folder(dialog, folder.as_deref());
                 // The signature's page, rectangle and field refer to the document as it is now:
                 // the pick is dropped (with a notice) if it is edited or switched away from
                 // meanwhile. Once the picker shows, the dialog closes; an error from here on