fix(ui-egui): keep an ink file that cannot all be read before writing over it (#157)

crates/ui-egui/src/app.rs

@@ -1664,6 +1664,7 @@ impl NoteCraftApp {
                 return;
             }
         }
+        self.tell_kept_ink();
         if let Some(ed) = self.editor.as_mut() {
             ed.blocks.retain(|b| !matches!(b, Block::Image { src, .. } if crate::inkpad::is_old_sheet(src)));
             ed.rebuild_body();
@@ -3856,6 +3857,7 @@ impl NoteCraftApp {
             Ok(()) => self.say(crate::i18n::format_message_id("ui.took_the_last_stroke_back_count_left", &[("count", &left.to_string())])),
             Err(e) => self.complain(&crate::i18n::format_message_id("ui.cannot_write_the_drawing_error", &[("error", &e.to_string())])),
         }
+        self.tell_kept_ink();
         // The page stops naming ink it no longer has.
         self.sync_ink_reference();
     }
@@ -4190,6 +4192,15 @@ impl NoteCraftApp {
         self.say(crate::tl_id!("ui.write_anywhere_on_the_page"));
     }
 
+    /// Says where the page's ink file was kept, when writing the ink kept it first because it
+    /// held more than could be read back as strokes (issue #157).
+    fn tell_kept_ink(&mut self) {
+        let Some(kept) = self.pad.as_mut().and_then(|pad| pad.kept_original.take()) else { return };
+        let shown = self.shown(&kept);
+        log::warn!("the page's ink file held more than its strokes; the original was kept: {kept:?}");
+        self.say(crate::i18n::format_message_id("ui.kept_the_original_drawing_file_path", &[("path", &shown)]));
+    }
+
     /// Writes the drawing again with no pen readings in it, for sending somewhere else.
     fn ink_export_plain(&mut self) {
         let Some(pad) = self.pad.as_ref() else {
@@ -6026,6 +6037,7 @@ impl NoteCraftApp {
                 Ok(()) => self.say(crate::i18n::format_message_id("ui.drawing_saved_count_strokes", &[("count", &strokes.to_string())])),
                 Err(e) => self.complain(&crate::i18n::format_message_id("ui.cannot_write_the_drawing_error", &[("error", &e.to_string())])),
             }
+            self.tell_kept_ink();
             self.sync_ink_reference();
         }
         if let Some(href) = follow {

crates/ui-egui/src/inkpad.rs

@@ -84,6 +84,11 @@ pub struct Pad {
     pub dirty: bool,
     /// How many strokes in the file were a picture only, with no readings to give back.
     pub flat: usize,
+    /// The file holds more than `drawing` does: it could not be read, or some of its lines are
+    /// a picture only. Before the file is first written over, it is kept beside the ink.
+    pub incomplete: bool,
+    /// Where that file was kept, once it has been, for the window to say so.
+    pub kept_original: Option<PathBuf>,
     /// The stroke being drawn now, if the pen is down.
     drawing_now: Option<Stroke>,
     /// The strokes being held, by their place in the drawing. Never written to the file:
@@ -128,13 +133,21 @@ impl Pad {
     /// drawn on, so a page nobody has drawn on stays as clean as it was.
     pub fn of_page(page_dir: &Path) -> Pad {
         let file = page_dir.join(FILE);
-        let (drawing, flat) =
-            std::fs::read_to_string(&file).ok().and_then(|text| svg::read(&text).ok()).unwrap_or_else(|| (Drawing::new(SHEET_W, SHEET_H), 0));
+        let read = std::fs::read_to_string(&file).ok().and_then(|text| svg::read(&text).ok());
+        // A file that is there but could not be read, or that holds lines with no readings,
+        // would lose them the first time the ink is written (issue #157).
+        let incomplete = match &read {
+            Some((_, flat)) => *flat > 0,
+            None => file.exists(),
+        };
+        let (drawing, flat) = read.unwrap_or_else(|| (Drawing::new(SHEET_W, SHEET_H), 0));
         Pad {
             file,
             drawing,
             dirty: false,
             flat,
+            incomplete,
+            kept_original: None,
             drawing_now: None,
             held: Vec::new(),
             loop_now: Vec::new(),
@@ -154,6 +167,13 @@ impl Pad {
         if let Some(parent) = self.file.parent() {
             std::fs::create_dir_all(parent)?;
         }
+        // The file holds what this drawing does not: it is kept, as it was, before it is
+        // written over or taken away, and only then (issue #157).
+        if self.incomplete && self.file.is_file() {
+            let kept = self.keep_original()?;
+            self.kept_original = Some(kept);
+        }
+        self.incomplete = false;
         // A page drawn on and then rubbed clean loses its file rather than keeping an
         // empty one, so a page with no ink has no ink in its folder either.
         if self.drawing.is_empty() {
@@ -169,6 +189,26 @@ impl Pad {
         Ok(())
     }
 
+    /// Copies the ink file as it is to `ink.svg.bak`, or the first free `ink-N.svg.bak`, beside
+    /// it. Not an `.svg`, so nothing takes the copy for the page's ink or for a picture of it.
+    fn keep_original(&self) -> std::io::Result<PathBuf> {
+        let folder = self.file.parent().map(Path::to_path_buf).unwrap_or_default();
+        for n in 1usize..=10_000 {
+            let name = if n == 1 { format!("{FILE}.bak") } else { format!("ink-{n}.svg.bak") };
+            let kept = folder.join(name);
+            match std::fs::OpenOptions::new().write(true).create_new(true).open(&kept) {
+                Ok(mut out) => {
+                    let mut original = std::fs::File::open(&self.file)?;
+                    std::io::copy(&mut original, &mut out)?;
+                    return Ok(kept);
+                }
+                Err(e) if e.kind() == std::io::ErrorKind::AlreadyExists => continue,
+                Err(e) => return Err(e),
+            }
+        }
+        Err(std::io::Error::new(std::io::ErrorKind::AlreadyExists, "every name for keeping the original ink file is taken"))
+    }
+
     /// Writes it again as a plain picture, beside the ink, for sending somewhere else.
     /// Returns where it was written.
     pub fn save_plain(&self) -> std::io::Result<PathBuf> {
@@ -836,6 +876,47 @@ mod tests {
         assert!(pad.file.ends_with(FILE), "the ink sits beside the page: {}", pad.file.display());
     }
 
+    /// Issue #157: an ink file that holds lines with no readings, or that cannot be read at all,
+    /// is kept as it was before new ink is written over it, and only once.
+    #[test]
+    fn ink_that_cannot_all_be_read_is_kept_before_it_is_written_over() {
+        let original = "<svg xmlns=\"http://www.w3.org/2000/svg\"><path d=\"M10 10 L50 50\" stroke=\"red\"/></svg>";
+        for (label, text) in [("a picture's path", original), ("not an SVG at all", "this is not a drawing")] {
+            let t = TempDir::new("ink-keep-original");
+            let page = t.path().to_path_buf();
+            std::fs::write(page.join(FILE), text).expect("an ink file of someone else's");
+            let mut pad = Pad::of_page(&page);
+            assert!(pad.incomplete, "{label}: the file holds more than the strokes read from it");
+
+            assert!(pad.drawing.add(stroke(10.0)));
+            pad.dirty = true;
+            pad.save().expect("saved");
+            let kept = pad.kept_original.take().expect("the original was kept");
+            assert_eq!(kept, page.join("ink.svg.bak"), "{label}");
+            assert_eq!(std::fs::read_to_string(&kept).expect("kept"), text, "{label}: kept as it was");
+            assert!(!crate::inkpad::is_old_sheet("ink.svg.bak"));
+
+            // Saving again does not keep another copy: the file is NoteCraft's own now.
+            assert!(pad.drawing.add(stroke(20.0)));
+            pad.save().expect("saved again");
+            assert_eq!(pad.kept_original, None, "{label}");
+            assert!(!page.join("ink-2.svg.bak").exists(), "{label}");
+        }
+
+        // A file of NoteCraft's own, read whole, is written over as before, with nothing kept.
+        let t = TempDir::new("ink-keep-own");
+        let page = t.path().to_path_buf();
+        let mut pad = Pad::of_page(&page);
+        assert!(pad.drawing.add(stroke(10.0)));
+        pad.save().expect("saved");
+        let mut again = Pad::of_page(&page);
+        assert!(!again.incomplete);
+        assert!(again.drawing.add(stroke(30.0)));
+        again.save().expect("saved");
+        assert_eq!(again.kept_original, None);
+        assert!(!page.join("ink.svg.bak").exists());
+    }
+
     #[test]
     fn ink_is_written_beside_the_page_and_comes_back_as_strokes() {
         let t = TempDir::new("ink-layer-save");

i18n/ar-XB.tsv

@@ -335,6 +335,7 @@
 @id	ui.json	[[RLI]]$$$JSON@@@[[PDI]]
 @id	ui.justification_goes_on_a_paragraph_of_text	[[RLI]]$$$Justification goes on a paragraph of text@@@[[PDI]]
 @id	ui.keep_this_window_above_the_others	[[RLI]]$$$Keep this window above the others@@@[[PDI]]
+@id	ui.kept_the_original_drawing_file_path	[[RLI]]$$$This page's drawing file held lines NoteCraft cannot edit. The file as it was is kept as {path}.@@@[[PDI]]
 @id	ui.label	[[RLI]]$$$label@@@[[PDI]]
 @id	ui.label_not_built	[[RLI]]$$${label} (not built)@@@[[PDI]]
 @id	ui.label_not_built_yet	[[RLI]]$$${label}: not built yet@@@[[PDI]]

i18n/ar.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	التبرير ينطبق على فقرة نصية
 @id	ui.keep_this_window_above_the_others	إبقاء هذه النافذة فوق النوافذ الأخرى
+@id	ui.kept_the_original_drawing_file_path	احتوى ملف الرسم في هذه الصفحة على خطوط لا يستطيع NoteCraft تحريرها. تم الاحتفاظ بالملف الأصلي باسم {path}.
 @id	ui.label	تسمية
 @id	ui.label_not_built	{label} (غير مبنٍ)
 @id	ui.label_not_built_yet	{label}: لم يُبنَ بعد

i18n/de.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	Der Textausrichtung bezieht sich auf einen Absatz
 @id	ui.keep_this_window_above_the_others	Dieses Fenster immer im Vordergrund halten
+@id	ui.kept_the_original_drawing_file_path	Die Zeichnungsdatei dieser Seite enthielt Linien, die NoteCraft nicht bearbeiten kann. Die ursprüngliche Datei ist als {path} aufbewahrt.
 @id	ui.label	Beschriftung
 @id	ui.label_not_built	{label} (nicht implementiert)
 @id	ui.label_not_built_yet	{label}: noch nicht implementiert

i18n/en-XA.tsv

@@ -335,6 +335,7 @@
 @id	ui.json	$$$JSON@@@
 @id	ui.justification_goes_on_a_paragraph_of_text	$$$Justification goes on a paragraph of text@@@
 @id	ui.keep_this_window_above_the_others	$$$Keep this window above the others@@@
+@id	ui.kept_the_original_drawing_file_path	$$$This page's drawing file held lines NoteCraft cannot edit. The file as it was is kept as {path}.@@@
 @id	ui.label	$$$label@@@
 @id	ui.label_not_built	$$${label} (not built)@@@
 @id	ui.label_not_built_yet	$$${label}: not built yet@@@

i18n/en.tsv

@@ -335,6 +335,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	Justification goes on a paragraph of text
 @id	ui.keep_this_window_above_the_others	Keep this window above the others
+@id	ui.kept_the_original_drawing_file_path	This page's drawing file held lines NoteCraft cannot edit. The file as it was is kept as {path}.
 @id	ui.label	label
 @id	ui.label_not_built	{label} (not built)
 @id	ui.label_not_built_yet	{label}: not built yet

i18n/es.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	La justificación se aplica a un párrafo de texto
 @id	ui.keep_this_window_above_the_others	Mantener esta ventana por encima de las demás
+@id	ui.kept_the_original_drawing_file_path	El archivo de dibujo de esta página tenía trazos que NoteCraft no puede editar. El archivo original se conserva como {path}.
 @id	ui.label	label
 @id	ui.label_not_built	{label} (no compilado)
 @id	ui.label_not_built_yet	{label}: aún no compilado

i18n/fa.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	تراز متن در یک بند اعمال می‌شود
 @id	ui.keep_this_window_above_the_others	این پنجره را بالای سایر پنجره‌ها نگه دارید
+@id	ui.kept_the_original_drawing_file_path	فایل طراحی این صفحه خط‌هایی داشت که NoteCraft نمی‌تواند ویرایش کند. فایل اصلی با نام {path} نگه داشته شد.
 @id	ui.label	برچسب
 @id	ui.label_not_built	{label} (ساخته نشده)
 @id	ui.label_not_built_yet	{label}: هنوز ساخته نشده

i18n/fr.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	La justification s'applique à un paragraphe de texte
 @id	ui.keep_this_window_above_the_others	Garder cette fenêtre au-dessus des autres
+@id	ui.kept_the_original_drawing_file_path	Le fichier de dessin de cette page contenait des traits que NoteCraft ne peut pas modifier. Le fichier d’origine est conservé sous {path}.
 @id	ui.label	label
 @id	ui.label_not_built	{label} (non implémenté)
 @id	ui.label_not_built_yet	{label} : pas encore implémenté

i18n/he.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	יישור מתייחס לפסקת טקסט
 @id	ui.keep_this_window_above_the_others	החזק חלון זה מעל האחרים
+@id	ui.kept_the_original_drawing_file_path	קובץ הציור של דף זה הכיל קווים ש-NoteCraft אינו יכול לערוך. הקובץ המקורי נשמר בשם {path}.
 @id	ui.label	תווית
 @id	ui.label_not_built	{label} (לא בנוי)
 @id	ui.label_not_built_yet	{label}: טרם נבנה

i18n/hi.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	पंक्तिबद्धता पाठ के पैराग्राफ पर लागू होती है
 @id	ui.keep_this_window_above_the_others	इस विंडो को अन्य विंडोओं से ऊपर रखें
+@id	ui.kept_the_original_drawing_file_path	इस पेज की ड्रॉइंग फ़ाइल में ऐसी रेखाएँ थीं जिन्हें NoteCraft संपादित नहीं कर सकता। मूल फ़ाइल {path} के रूप में रखी गई है।
 @id	ui.label	लेबल
 @id	ui.label_not_built	{label} (बिल्ड नहीं हुआ)
 @id	ui.label_not_built_yet	{label}: अभी तक बिल्ड नहीं हुआ

i18n/ja.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	段落のテキストに対して適用されます
 @id	ui.keep_this_window_above_the_others	このウィンドウを他のウィンドウの上に固定する
+@id	ui.kept_the_original_drawing_file_path	このページの描画ファイルには NoteCraft で編集できない線が含まれていました。元のファイルは {path} として保存されています。
 @id	ui.label	ラベル
 @id	ui.label_not_built	{label} (未実装)
 @id	ui.label_not_built_yet	{label}: まだ実装されていません

i18n/ko.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	정렬은 텍스트 단락에 적용됩니다
 @id	ui.keep_this_window_above_the_others	이 창을 다른 창 위에 고정
+@id	ui.kept_the_original_drawing_file_path	이 페이지의 그리기 파일에 NoteCraft에서 편집할 수 없는 선이 있었습니다. 원래 파일은 {path}(으)로 보관되었습니다.
 @id	ui.label	레이블
 @id	ui.label_not_built	{label} (미구현)
 @id	ui.label_not_built_yet	{label}: 아직 구현되지 않음

i18n/ru.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	Выравнивание применяется к абзацу текста
 @id	ui.keep_this_window_above_the_others	Держать это окно поверх остальных
+@id	ui.kept_the_original_drawing_file_path	Файл рисунка этой страницы содержал линии, которые NoteCraft не может изменить. Исходный файл сохранён как {path}.
 @id	ui.label	метка
 @id	ui.label_not_built	{label} (не реализовано)
 @id	ui.label_not_built_yet	{label}: ещё не реализовано

i18n/ur.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	جسٹیفیکیشن متن کے ایک پیراگراف پر لاگو ہوتی ہے
 @id	ui.keep_this_window_above_the_others	اس ونڈو کو دوسروں کے اوپر رکھیں
+@id	ui.kept_the_original_drawing_file_path	اس صفحے کی ڈرائنگ فائل میں ایسی لکیریں تھیں جنہیں NoteCraft مدون نہیں کر سکتا۔ اصل فائل {path} کے نام سے محفوظ رکھی گئی ہے۔
 @id	ui.label	لیبل
 @id	ui.label_not_built	{label} (بنایا نہیں گیا)
 @id	ui.label_not_built_yet	{label}: ابھی تک نہیں بنایا گیا

i18n/zh.tsv

@@ -322,6 +322,7 @@
 @id	ui.json	JSON
 @id	ui.justification_goes_on_a_paragraph_of_text	对齐方式应用于一段文本
 @id	ui.keep_this_window_above_the_others	保持此窗口位于其他窗口之上
+@id	ui.kept_the_original_drawing_file_path	此页面的绘图文件包含 NoteCraft 无法编辑的线条。原始文件已保存为 {path}。
 @id	ui.label	标签
 @id	ui.label_not_built	{label}（未构建）
 @id	ui.label_not_built_yet	{label}：尚未构建