fix(print): persist paper override flag and refine driver paper selection

crates/ui-egui/src/app/prefs.rs

@@ -161,6 +161,7 @@ impl PdfCraftApp {
         );
         let size = self.print_draft.paper_size();
         v["print_paper_size"] = serde_json::json!([size.0, size.1]);
+        v["print_paper_overridden"] = serde_json::json!(self.print_draft.paper_overridden);
         v.to_string()
     }
 
@@ -287,6 +288,7 @@ impl PdfCraftApp {
                 self.print_draft.papers.push((name.to_string(), size));
                 self.print_draft.paper = self.print_draft.papers.len() - 1;
             }
+            self.print_draft.paper_overridden = v.get("print_paper_overridden").and_then(serde_json::Value::as_bool).unwrap_or(true);
         }
         if let Some(on) = v["highlight_fields"].as_bool() {
             self.view_defaults.highlight_fields = on;

crates/ui-egui/src/workflows/print_ui.rs

@@ -172,7 +172,7 @@ impl PdfCraftApp {
             ..keep
         };
         self.print_draft.update_printer_papers();
-        if !picked && !self.print_draft.paper_overridden && self.print_draft.paper == 0 {
+        if !picked && !self.print_draft.paper_overridden {
             self.print_draft.auto_select_default_paper();
         }
         self.dialog = Some(crate::Dialog::Print);
@@ -318,7 +318,7 @@ impl PdfCraftApp {
                         d.printer_picked = false;
                         d.printer = default_printer(&printers);
                         d.update_printer_papers();
-                        if !d.paper_overridden && d.paper == 0 {
+                        if !d.paper_overridden {
                             d.auto_select_default_paper();
                         }
                     }

crates/ui-egui/src/workflows/print_ui/body.rs

@@ -214,10 +214,13 @@ pub(crate) fn body(
                 let paper_label = ui.label(tl!("Paper:"));
                 let paper_name = d.paper_name().to_string();
                 let before = d.paper;
+                let mut paper_clicked = false;
                 ui.horizontal(|ui| {
                     craft_ui::ComboBox::from_id_salt("paper").selected_text(tl!(&paper_name)).width(180.0).show_ui(ui, |ui| {
                         for (i, (name, _)) in d.papers.iter().enumerate() {
-                            ui.selectable_value(&mut d.paper, i, tl!(name));
+                            if ui.selectable_value(&mut d.paper, i, tl!(name)).clicked() {
+                                paper_clicked = true;
+                            }
                         }
                     })
                     .response
@@ -246,7 +249,7 @@ pub(crate) fn body(
                     d.paper_overridden = true;
                 }
                 // Label stock gets the label layout (cut, turned upright, fitted).
-                if d.paper != before && d.paper == print::LABEL_PAPER {
+                if paper_clicked && d.paper != before && d.paper == print::LABEL_PAPER {
                     d.paper_before_label = Some(before);
                     d.handling = Handling::Label;
                     d.sheet = 0;
@@ -281,6 +284,7 @@ pub(crate) fn body(
                         && let Some(paper) = matched
                     {
                         d.paper = paper;
+                        d.paper_overridden = true;
                         // A paper picked outright: nothing for leaving Label to give back.
                         d.paper_before_label = None;
                         d.handling = Handling::Size;

crates/ui-egui/src/workflows/print_ui/draft.rs

@@ -168,10 +168,14 @@ impl PrintDraft {
 
     /// Refresh `self.papers` with driver-reported media sizes, preserving the current selection.
     pub fn update_printer_papers(&mut self) {
+        let before_label_name = self.paper_before_label.and_then(|idx| self.papers.get(idx).map(|p| p.0.clone()));
         let mut papers = default_papers();
         if let Some(ref printer) = self.printer {
             let detected = spool::printer_papers(printer);
             for (name, size) in detected {
+                if !(size.0 >= 72.0 && size.1 >= 72.0 && size.0.is_finite() && size.1.is_finite()) {
+                    continue;
+                }
                 let norm = (size.0.min(size.1), size.0.max(size.1));
                 if !papers.iter().any(|(_, s)| {
                     let s_norm = (s.0.min(s.1), s.0.max(s.1));
@@ -192,6 +196,7 @@ impl PrintDraft {
             self.papers.push((current_name, current_size));
             self.paper = self.papers.len() - 1;
         }
+        self.paper_before_label = before_label_name.and_then(|name| self.papers.iter().position(|(n, _)| n == &name));
     }
 
     /// Auto-select the printer's configured default paper (from DEVMODE / driver settings).
@@ -199,7 +204,9 @@ impl PrintDraft {
         if let Some(ref printer) = self.printer
             && let Some((name, size)) = spool::printer_default_paper(printer)
         {
+            let overridden = self.paper_overridden;
             self.apply_driver_paper(name, size);
+            self.paper_overridden = overridden;
         }
     }
 

crates/ui-egui/tests/it/print.rs

@@ -791,9 +791,10 @@ fn paper_choice_survives_cancel_and_settings_restore() {
     let saved = h.state().persist();
     let json: serde_json::Value = serde_json::from_str(&saved).unwrap();
     assert_eq!(json["print_paper"], "A4", "store the canonical name, not its position");
+    assert_eq!(json["print_paper_overridden"], true, "explicitly chosen paper records override flag");
     let mut app = PdfCraftApp::new();
     app.restore(&saved);
-    let expected = pdfcraft_ui_egui::PrintDraft { paper: a4, ..Default::default() };
+    let expected = pdfcraft_ui_egui::PrintDraft { paper: a4, paper_overridden: true, ..Default::default() };
     assert_eq!(app.print_draft, expected, "no other print preference becomes persistent");
     let mut restarted = harness_with_settings(Some(saved));
     assert!(restarted.state_mut().execute("print.dialog"));