launcher: keep the cause when a config's ROM cannot be read

src/video/ui.rs

@@ -3919,7 +3919,12 @@ fn clip_path_tail(text: &str, avail_px: usize) -> String {
 /// rather than cutting into the name. Splits on both `/` and `\` so Windows and
 /// Unix paths work. If even the name alone is too wide, its tail is shown.
 fn clip_path_keep_name(text: &str, avail_px: usize) -> String {
-    let max_chars = avail_px / font::GLYPH_W;
+    clip_path_to_chars(text, avail_px / font::GLYPH_W)
+}
+
+/// [`clip_path_keep_name`] in characters rather than pixels, shared with the
+/// status line (see `window::shorten_status_paths`).
+pub(super) fn clip_path_to_chars(text: &str, max_chars: usize) -> String {
     if text.chars().count() <= max_chars {
         return text.to_string();
     }
@@ -3942,7 +3947,7 @@ fn clip_path_keep_name(text: &str, avail_px: usize) -> String {
         prefixed
     } else {
         // The file name alone does not fit; fall back to a plain tail clip.
-        clip_path_tail(name, avail_px)
+        clip_path_tail(name, max_chars * font::GLYPH_W)
     }
 }
 

src/video/window.rs

@@ -2610,12 +2610,49 @@ fn classify_dropped_media(path: &std::path::Path) -> DroppedMediaKind {
     }
 }
 
+/// Shorten any filesystem path in a status message so its file name stays
+/// visible: a long path keeps its final component behind a "..." prefix instead
+/// of running past the panel. Windows and Unix paths both work.
+///
+/// `anyhow`'s alternate Display joins the error chain with `": "`, and a path
+/// sits at the end of its segment (`reading ROM <path>`), so each segment is
+/// clipped as one span. That keeps paths containing spaces intact instead of
+/// splitting them into several fragments.
+fn shorten_status_paths(msg: &str) -> String {
+    // Enough for the file name plus a directory or two, leaving room for the
+    // cause after it; the status line holds roughly eighty characters.
+    const MAX_PATH_CHARS: usize = 28;
+    msg.split(": ")
+        .map(|segment| {
+            let Some(sep) = segment.find(['/', '\\']) else {
+                return segment.to_string();
+            };
+            // The path runs from the token holding the first separator (back up
+            // to the preceding space) to the end of the segment.
+            let start = segment[..sep].rfind(' ').map_or(0, |i| i + 1);
+            let (prose, path) = segment.split_at(start);
+            format!("{prose}{}", ui::clip_path_to_chars(path, MAX_PATH_CHARS))
+        })
+        .collect::<Vec<_>>()
+        .join(": ")
+}
+
 /// A one-line, length-bounded form of an error for the configuration panel's
-/// status line (the full chain still goes to the log).
+/// status line. `{:#}` walks the whole chain, so the cause is kept: showing
+/// only the outermost context turned "reading ROM <path>" into what looked like
+/// a progress message when the ROM was simply not there. Paths are shortened to
+/// their file name and the first letter capitalised so it reads as a sentence
+/// instead of trailing off past the edge of the panel.
 fn short_status_error(err: &anyhow::Error) -> String {
-    let msg = err.to_string();
+    let msg = format!("{err:#}");
     let first_line = msg.lines().next().unwrap_or("").trim();
-    first_line.chars().take(96).collect()
+    let shortened = shorten_status_paths(first_line);
+    let mut chars = shortened.chars();
+    let sentence = match chars.next() {
+        Some(first) => first.to_uppercase().collect::<String>() + chars.as_str(),
+        None => String::new(),
+    };
+    sentence.chars().take(96).collect()
 }
 
 fn set_mouse_button(emu: &mut Emulator, port: u8, button: MouseButtonKind, pressed: bool) {
@@ -4529,12 +4566,16 @@ impl App {
         let mut cfg = match self.launcher_state().map(|s| s.setup.build_config()) {
             Some(Ok(cfg)) => cfg,
             Some(Err(e)) => {
+                // The status line is one shortened sentence; the log keeps the
+                // whole chain (which names the underlying cause).
+                warn!("run failed: {e:#}");
                 self.set_launcher_status(StatusMessage::err(short_status_error(&e)));
                 return;
             }
             None => return,
         };
         if let Err(e) = crate::config::resolve_bundled_rom(&mut cfg) {
+            warn!("run failed: {e:#}");
             self.set_launcher_status(StatusMessage::err(short_status_error(&e)));
             return;
         }
@@ -4564,6 +4605,7 @@ impl App {
         let emu = match crate::emulator::build_machine(&cfg, audio, true, false) {
             Ok(emu) => emu,
             Err(e) => {
+                warn!("run failed: {e:#}");
                 self.set_launcher_status(StatusMessage::err(short_status_error(&e)));
                 return;
             }

src/video/window/tests.rs

@@ -14,18 +14,18 @@ use super::{
     parse_amiga_key, pause_button_rect, power_button_rect, present_height,
     presentation_h_shift_for, presentation_source_y_offset, raw_device_qualifier_family_held,
     raw_device_qualifier_rawkey, rawkey_is_held, rawkey_transition_is_duplicate,
-    reboot_button_rect, repeated_main_key_should_drop, rgba, shot_button_rect,
-    should_render_emulated_frame, standard_window_top_row, status_with_latched_fdd_track,
-    take_integral_mouse_delta, texture_height, texture_width, tv_aperture_source_row,
-    tv_source_h_bounds, volume_percent_from_pos, volume_slider_track_rect, BarControl, DriveBar,
-    JoystickInputMode, KeyboardJoystickHeld, KeyboardJoystickKey, MediaBar, StatusBarView,
-    ToolPanelKind, AMIGA_RAWKEY_LEFT_ALT, AMIGA_RAWKEY_LEFT_SHIFT, AMIGA_RAWKEY_RIGHT_ALT,
-    AMIGA_RAWKEY_RIGHT_SHIFT, BUTTON_GLYPH, BUTTON_GLYPH_DISABLED, CD_BODY, CD_LED_OFF, CD_LED_ON,
-    DISK_BODY, DISK_BODY_SHADOW, DISK_LABEL, FDD_LED_OFF, FDD_LED_ON, HDD_LED_OFF, HDD_LED_ON,
-    POWER_GLYPH_OFF, POWER_GLYPH_ON, POWER_LED_OFF, POWER_LED_ON, STANDARD_PAL_VISIBLE_LINES,
-    STANDARD_PAL_VISIBLE_START_VPOS, STATUS_BG, TRACK_SEGMENT_OFF, TRACK_SEGMENT_ON,
-    TV_PAL_LIVE_PAD_X, TV_PAL_PRESENT_HEIGHT, TV_PAL_PRESENT_SOURCE_X, TV_PAL_PRESENT_SOURCE_Y,
-    TV_PAL_PRESENT_WIDTH, VOLUME_FILL, VOLUME_GLYPH_X,
+    reboot_button_rect, repeated_main_key_should_drop, rgba, short_status_error,
+    shorten_status_paths, shot_button_rect, should_render_emulated_frame, standard_window_top_row,
+    status_with_latched_fdd_track, take_integral_mouse_delta, texture_height, texture_width,
+    tv_aperture_source_row, tv_source_h_bounds, volume_percent_from_pos, volume_slider_track_rect,
+    BarControl, DriveBar, JoystickInputMode, KeyboardJoystickHeld, KeyboardJoystickKey, MediaBar,
+    StatusBarView, ToolPanelKind, AMIGA_RAWKEY_LEFT_ALT, AMIGA_RAWKEY_LEFT_SHIFT,
+    AMIGA_RAWKEY_RIGHT_ALT, AMIGA_RAWKEY_RIGHT_SHIFT, BUTTON_GLYPH, BUTTON_GLYPH_DISABLED, CD_BODY,
+    CD_LED_OFF, CD_LED_ON, DISK_BODY, DISK_BODY_SHADOW, DISK_LABEL, FDD_LED_OFF, FDD_LED_ON,
+    HDD_LED_OFF, HDD_LED_ON, POWER_GLYPH_OFF, POWER_GLYPH_ON, POWER_LED_OFF, POWER_LED_ON,
+    STANDARD_PAL_VISIBLE_LINES, STANDARD_PAL_VISIBLE_START_VPOS, STATUS_BG, TRACK_SEGMENT_OFF,
+    TRACK_SEGMENT_ON, TV_PAL_LIVE_PAD_X, TV_PAL_PRESENT_HEIGHT, TV_PAL_PRESENT_SOURCE_X,
+    TV_PAL_PRESENT_SOURCE_Y, TV_PAL_PRESENT_WIDTH, VOLUME_FILL, VOLUME_GLYPH_X,
 };
 use crate::audio::{AudioSink, NullSink};
 use crate::bus::{FrontPanelStatus, RenderRegisterSnapshot};
@@ -4087,3 +4087,57 @@ mod control_drain {
         );
     }
 }
+
+#[test]
+fn a_missing_rom_reads_as_a_failure_with_a_shortened_path() {
+    // A config naming a ROM that is not there must say so, not read like a
+    // progress message, and must not run the whole path past the panel. A
+    // synthetic NotFound cause keeps this deterministic and off the filesystem.
+    let cause = std::io::Error::new(std::io::ErrorKind::NotFound, "no such file");
+    let err = anyhow::Error::new(cause)
+        .context("reading ROM /Users/me/Desktop/Amiga/kickstarts/roms/kick31.rom".to_string());
+
+    // The cause is what says it failed, so it must survive; the path is
+    // shortened to keep the whole line inside the panel.
+    let status = short_status_error(&err);
+    assert!(
+        status.starts_with("Reading ROM .../roms/kick31.rom:"),
+        "{status}"
+    );
+    assert!(status.contains("no such file"), "{status}");
+    assert!(!status.contains("/Users/me/Desktop"), "{status}");
+    assert!(status.chars().count() <= 80, "{status}");
+}
+
+#[test]
+fn status_paths_keep_the_file_name() {
+    // Short paths are left alone.
+    let short = "unable to read ROM roms/kick.rom";
+    assert_eq!(shorten_status_paths(short), short);
+
+    // A long Unix path collapses to its file name.
+    let unix = "unable to read ROM /Users/me/Desktop/Amiga/roms/kickstart31.rom";
+    let out = shorten_status_paths(unix);
+    assert!(out.ends_with("kickstart31.rom"), "{out}");
+    assert!(out.contains("..."), "{out}");
+
+    // A long Windows path keeps its separator and file name.
+    let win = r"unable to read ROM C:\Users\me\Documents\Amiga\roms\kickstart31.rom";
+    let out = shorten_status_paths(win);
+    assert!(out.ends_with("kickstart31.rom"), "{out}");
+    assert!(out.contains('\\'), "{out}");
+
+    // A path containing spaces is clipped as one span, not split apart into
+    // several "..." fragments, and the cause after it survives.
+    let spaced = "reading ROM /Users/me/My Amiga Roms/kickstart31.rom: no such file";
+    let out = shorten_status_paths(spaced);
+    assert!(out.contains("kickstart31.rom"), "{out}");
+    assert!(out.ends_with(": no such file"), "{out}");
+    assert_eq!(out.matches("...").count(), 1, "{out}");
+
+    // The cause is kept behind the "reading ROM" context (Display's ": " chain).
+    let with_cause =
+        "unable to read extended ROM /Users/me/Desktop/Amiga/roms/cd32ext.rom: No such file";
+    let out = shorten_status_paths(with_cause);
+    assert!(out.contains("cd32ext.rom: No such file"), "{out}");
+}