Warn, not panic, on invalid fonts (#22491)

# Objective

Fix panics due to invalid legacy fonts that we can't generate glyph
images from.

Fixes #22475

## Solution
* In `text_system` and `update_text2d_layout`, instead of panicking on
`TextError::FailedToGetGlyphImage`, `warn_once` and clear the text
layout.

* Given an invalid font, Cosmic Text returns an invalid text layout with
infinite text bounds. If Cosmic Text returns non-finite bounds, return a
zero size from the `buffer_dimensions` function.

* Added a `get_face_details` method to `CosmicFontSystem` to provide
better info for the warning messages.

`buffer_dimensions` probably should be reworked to return a `Result`,
with the text systems emitting a warning on invalid layout bounds. Not
so important though, left for a follow up.

## Testing

The `system_fonts` example should no longer panic now. Instead the text
with the invalid font is not rendered:

<img width="869" height="166" alt="system-fonts-list-fixed"
src="https://github.com/user-attachments/assets/a05cab45-68d2-453b-8fa6-16ec5b6bba76"
/>

One of the problematic fonts:
https://github.com/justrajdeep/fonts/blob/master/NISC18030.ttf

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>

crates/bevy_sprite/src/text2d.rs

@@ -259,9 +259,15 @@ pub fn update_text2d_layout(
                     reprocess_queue.insert(entity);
                     continue;
                 }
+                Err(e @ TextError::FailedToGetGlyphImage(key)) => {
+                    bevy_log::warn_once!(
+                        "{e}. Face: {:?}",
+                        font_system.get_face_details(key.font_id)
+                    );
+                    text_layout_info.clear();
+                }
                 Err(
                     e @ (TextError::FailedToAddGlyph(_)
-                    | TextError::FailedToGetGlyphImage(_)
                     | TextError::MissingAtlasLayout
                     | TextError::MissingAtlasTexture
                     | TextError::InconsistentAtlasState),

crates/bevy_text/src/pipeline.rs

@@ -12,8 +12,8 @@ use bevy_reflect::{std_traits::ReflectDefault, Reflect};
 
 use crate::{
     add_glyph_to_atlas, error::TextError, get_glyph_atlas_info, ComputedTextBlock, Font,
-    FontAtlasKey, FontAtlasSet, FontHinting, FontSmoothing, FontSource, Justify, LineBreak,
-    LineHeight, PositionedGlyph, TextBounds, TextEntity, TextFont, TextLayout,
+    FontAtlasKey, FontAtlasSet, FontHinting, FontSmoothing, FontSource, FontStyle, FontWeight,
+    Justify, LineBreak, LineHeight, PositionedGlyph, TextBounds, TextEntity, TextFont, TextLayout,
 };
 use cosmic_text::{Attrs, Buffer, Family, Metrics, Shaping, Wrap};
 
@@ -34,6 +34,83 @@ impl Default for CosmicFontSystem {
     }
 }
 
+impl CosmicFontSystem {
+    /// Get information about a font face, if it exists
+    pub fn get_face_details(&self, id: cosmic_text::fontdb::ID) -> Option<FontFaceDetails> {
+        self.0.db().face(id).map(FontFaceDetails::from)
+    }
+}
+
+#[derive(Debug)]
+/// Details about a Font Face
+pub struct FontFaceDetails {
+    /// The path of the source file, if the font was loaded from a file.
+    pub path: Option<std::path::PathBuf>,
+
+    /// The face's index in the font data.
+    pub index: u32,
+
+    /// A list of family names.
+    ///
+    /// Contains pairs of Name + Language. Where the first family is always English US,
+    /// unless it's missing from the font.
+    ///
+    /// Corresponds to a *Typographic Family* (ID 16) or a *Font Family* (ID 1) [name ID]
+    /// in a TrueType font.
+    ///
+    /// This is not an *Extended Typographic Family* or a *Full Name*.
+    /// Meaning it will contain _Arial_ and not _Arial Bold_.
+    ///
+    /// [name ID]: https://docs.microsoft.com/en-us/typography/opentype/spec/name#name-ids
+    pub families: Vec<(String, String)>,
+
+    /// A PostScript name.
+    ///
+    /// Corresponds to a *PostScript name* (6) [name ID] in a TrueType font.
+    ///
+    /// [name ID]: https://docs.microsoft.com/en-us/typography/opentype/spec/name#name-ids
+    pub post_script_name: String,
+
+    /// A font face style.
+    pub style: FontStyle,
+
+    /// A font face weight.
+    pub weight: FontWeight,
+
+    /// A font face stretch.
+    pub stretch: u16,
+
+    /// Indicates that the font face is monospaced.
+    pub monospaced: bool,
+}
+
+impl From<&cosmic_text::fontdb::FaceInfo> for FontFaceDetails {
+    fn from(face: &cosmic_text::fontdb::FaceInfo) -> Self {
+        FontFaceDetails {
+            path: match face.source {
+                cosmic_text::fontdb::Source::Binary(_) => None,
+                cosmic_text::fontdb::Source::File(ref path)
+                | cosmic_text::fontdb::Source::SharedFile(ref path, _) => Some(path.clone()),
+            },
+            index: face.index,
+            families: face
+                .families
+                .iter()
+                .map(|(name, language)| (name.clone(), language.to_string()))
+                .collect(),
+            post_script_name: face.post_script_name.clone(),
+            style: match face.style {
+                cosmic_text::Style::Normal => FontStyle::Normal,
+                cosmic_text::Style::Italic => FontStyle::Italic,
+                cosmic_text::Style::Oblique => FontStyle::Oblique,
+            },
+            weight: FontWeight(face.weight.0),
+            stretch: face.stretch.to_number(),
+            monospaced: face.monospaced,
+        }
+    }
+}
+
 /// A wrapper resource around a [`cosmic_text::SwashCache`]
 ///
 /// The swash cache rasterizer is used to rasterize glyphs
@@ -511,7 +588,12 @@ fn buffer_dimensions(buffer: &Buffer) -> Vec2 {
         size.x = size.x.max(run.line_w);
         size.y += run.line_height;
     }
-    size.ceil()
+
+    if size.is_finite() {
+        size.ceil()
+    } else {
+        Vec2::ZERO
+    }
 }
 
 /// Discards stale data cached in `FontSystem`.

crates/bevy_ui/Cargo.toml

@@ -21,6 +21,7 @@ bevy_image = { path = "../bevy_image", version = "0.18.0-dev" }
 bevy_input = { path = "../bevy_input", version = "0.18.0-dev" }
 bevy_input_focus = { path = "../bevy_input_focus", version = "0.18.0-dev" }
 bevy_math = { path = "../bevy_math", version = "0.18.0-dev" }
+bevy_log = { path = "../bevy_log", version = "0.18.0-dev" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.18.0-dev" }
 bevy_sprite = { path = "../bevy_sprite", version = "0.18.0-dev", features = [
   "bevy_text",

crates/bevy_ui/src/widget/text.rs

@@ -15,6 +15,7 @@ use bevy_ecs::{
     world::Ref,
 };
 use bevy_image::prelude::*;
+use bevy_log::warn_once;
 use bevy_math::Vec2;
 use bevy_reflect::{std_traits::ReflectDefault, Reflect};
 use bevy_text::{
@@ -369,9 +370,13 @@ pub fn text_system(
                     // There was an error processing the text layout, try again next frame
                     text_flags.needs_recompute = true;
                 }
+                Err(e @ TextError::FailedToGetGlyphImage(key)) => {
+                    warn_once!("{e}. Face: {:?}", font_system.get_face_details(key.font_id));
+                    text_flags.needs_recompute = false;
+                    text_layout_info.clear();
+                }
                 Err(
                     e @ (TextError::FailedToAddGlyph(_)
-                    | TextError::FailedToGetGlyphImage(_)
                     | TextError::MissingAtlasLayout
                     | TextError::MissingAtlasTexture
                     | TextError::InconsistentAtlasState),