bug: Multi-codepoint emojis fail silently in theme.yml glyph field

[dcadenas]

Bug Description

Emojis with Unicode variation selectors (like 🖼️ and 🖥️) cause the entire theme.yml file to be silently ignored due to deserialization failure.

Reproduction Steps

1. Create ~/.config/eza/theme.yml with:

filenames:
  data: {icon: {glyph: 💾}}        # Works - single codepoint
  Pictures: {icon: {glyph: 🖼️}}    # Fails - has variation selector
  Desktop: {icon: {glyph: 🖥️}}     # Fails - has variation selector

2. Run eza -l --icons

Expected Behavior

All custom icons should display, including emojis with variation selectors.

Actual Behavior

• The data icon (💾) displays correctly
• Theme parsing fails silently when it encounters 🖼️ or 🖥️
• All subsequent icons in theme.yml are ignored
• User receives no error message

Root Cause

The glyph field in IconStyle and IconStyleOverride structs is defined as Option<char>:

src/theme/ui_styles.rs:18

pub struct IconStyle {
    pub glyph: Option<char>,  // ❌ Can only hold single Unicode scalar
    pub style: Option<Style>,
}

src/options/config.rs:210

pub struct IconStyleOverride {
    pub glyph: Option<char>,  // ❌ Same issue
    pub style: Option<StyleOverride>,
}

Rust's char type represents a single Unicode scalar value. However, many emojis consist of multiple codepoints:

Emoji	Description	Codepoints	Status
🖼️	Picture frame	U+1F5BC + U+FE0F	❌ Fails
🖥️	Desktop computer	U+1F5A5 + U+FE0F	❌ Fails
👨‍💻	Man technologist	U+1F468 + U+200D + U+1F4BB	❌ Fails
🇺🇸	US flag	U+1F1FA + U+1F1F8	❌ Fails
💾	Floppy disk	U+1F4BE	✅ Works

The second codepoint (U+FE0F) is a variation selector - an invisible modifier that tells the system to render the character as a colorful emoji.

Silent Failure

src/options/config.rs:617-621

pub fn to_theme(&self) -> Option<UiStyles> {
    let ui_styles_override: Option<UiStylesOverride> = {
        let file = std::fs::File::open(&self.location).ok()?;
        serde_norway::from_reader(&file).ok()  // ❌ .ok() swallows errors!
    };
    FromOverride::from(ui_styles_override, Some(UiStyles::default()))
}

The .ok() converts deserialization errors into None, causing the entire theme.yml to be ignored with no warning.

Affected Emojis

This affects:

• ✅ Emojis with variation selectors (U+FE0F): 🖼️ 🖥️ ⌚️ ☎️
• ✅ ZWJ (Zero Width Joiner) sequences: 👨‍💻 👩‍🎨 👨‍👩‍👧‍👦
• ✅ Flag emojis (regional indicators): 🇺🇸 🇬🇧 🇯🇵
• ✅ Skin tone modifiers: 👋🏻 👋🏿
• ✅ Any other multi-codepoint emoji

Environment

• eza version: v0.23.4
• OS: Linux (affects all platforms)
• Shell: Any
• Terminal: Any

Proposed Solution

1. Change glyph field from Option<char> to Option<String> to support grapheme clusters
2. Add proper error handling to report deserialization failures instead of silently ignoring them

This would enable full emoji support while maintaining backward compatibility with existing single-character icons.