fix: walk directories when use extra theme paths

src/lib.rs

@@ -56,14 +56,15 @@ use theme::BASE_PATHS;
 
 use crate::cache::{CACHE, CacheEntry};
 use crate::theme::{THEMES, Theme, try_build_icon_path};
+use std::ffi::OsStr;
 use std::hash::{Hash, Hasher};
 use std::io::BufRead;
 use std::ops::ControlFlow;
 use std::path::PathBuf;
-use std::time::Instant;
 
 mod cache;
 mod theme;
+mod walk_dir;
 
 /// Return the list of installed themes on the system
 ///
@@ -274,29 +275,48 @@ impl<'a> LookupBuilder<'a> {
         }
 
         if !self.extra_paths.is_empty() {
-            let extensions = if self.force_svg {
-                [".svg", ".png", ".xpm"]
-            } else {
-                [".png", ".svg", ".xpm"]
-            };
-            let mut name_buf = String::new();
+            let mut svg_path = None;
+            let mut png_path = None;
+            let mut xpm_path = None;
 
-            let result = extensions
-                .into_iter()
-                .try_for_each(|ext| {
-                    self.extra_paths.iter().try_for_each(|dir| {
-                        let mut path = dir.clone();
-                        if try_build_icon_path(&mut path, &mut name_buf, self.name, ext) {
-                            return ControlFlow::Break(path);
+            for file_path in walk_dir::Iter::new(self.extra_paths.iter().cloned()) {
+                if let Some(file_name) = file_path.file_stem().and_then(OsStr::to_str)
+                    && file_name != self.name
+                {
+                    continue;
+                }
+
+                if let Some(this_ext) = file_path.extension().and_then(OsStr::to_str) {
+                    match this_ext {
+                        "svg" => {
+                            svg_path = Some(file_path);
+                            if self.force_svg || png_path.is_some() {
+                                break;
+                            }
                         }
-                        name_buf.clear();
-                        ControlFlow::Continue(())
-                    })
-                })
-                .break_value();
 
-            if result.is_some() {
-                return result;
+                        "png" => {
+                            png_path = Some(file_path);
+                            if !self.force_svg || svg_path.is_some() {
+                                break;
+                            }
+                        }
+
+                        "xpm" => {
+                            xpm_path = Some(file_path);
+                        }
+
+                        _ => (),
+                    }
+                }
+            }
+
+            if let Some(path) = if self.force_svg {
+                svg_path.or(png_path).or(xpm_path)
+            } else {
+                png_path.or(svg_path).or(xpm_path)
+            } {
+                return Some(path);
             }
         }
 

src/walk_dir.rs

@@ -0,0 +1,100 @@
+// Copyright 2026 System76 <info@system76.com>
+// SPDX-License-Identifier: MIT
+
+//! Search for files within multiple directories. Follows symlinks, avoids loops, and
+//! limits the max depth to 5.
+
+use std::{
+    collections::{BTreeSet, VecDeque},
+    fs,
+    path::PathBuf,
+};
+
+const MAX_DEPTH: usize = 5;
+
+pub struct Iter {
+    directories_to_walk: VecDeque<(PathBuf, usize)>,
+    actively_walking: Option<VecDeque<(PathBuf, usize)>>,
+    visited: BTreeSet<PathBuf>,
+}
+
+impl Iter {
+    /// Directories will be processed in order.
+    #[inline]
+    pub fn new<I: Iterator<Item = PathBuf>>(directories_to_walk: I) -> Self {
+        Self {
+            directories_to_walk: directories_to_walk.map(|dir| (dir, 0)).collect(),
+            actively_walking: None,
+            visited: BTreeSet::default(),
+        }
+    }
+}
+
+impl Iterator for Iter {
+    type Item = PathBuf;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        'outer: loop {
+            let mut paths = match self.actively_walking.take() {
+                Some(dir) => dir,
+                None => {
+                    while let Some((mut path, depth)) = self.directories_to_walk.pop_front() {
+                        path = path.canonicalize().map_or(path, |canonical| canonical);
+                        self.visited.insert(path.clone());
+                        match fs::read_dir(&path) {
+                            Ok(dir) => {
+                                self.actively_walking = Some({
+                                    // Pre-sort the walked directories as order of parsing affects appid matches.
+                                    let mut entries = dir
+                                        .filter_map(Result::ok)
+                                        .map(|entry| (entry.path(), depth))
+                                        .collect::<VecDeque<_>>();
+                                    entries.make_contiguous().sort_unstable();
+                                    entries
+                                });
+
+                                continue 'outer;
+                            }
+
+                            // Skip directories_to_walk which could not be read or that were already visited
+                            _ => continue,
+                        }
+                    }
+
+                    return None;
+                }
+            };
+
+            'inner: while let Some((mut path, mut depth)) = paths.pop_front() {
+                if !path.exists() {
+                    continue 'inner;
+                }
+
+                if path.is_dir() {
+                    depth += 1;
+
+                    if MAX_DEPTH == depth {
+                        continue;
+                    }
+
+                    path = match path.canonicalize() {
+                        Ok(canonicalized) => canonicalized,
+                        Err(_) => continue 'inner,
+                    };
+                }
+
+                if let Ok(metadata) = path.metadata() {
+                    if metadata.is_dir() {
+                        // Skip visited directories to mitigate against file system loops
+                        if self.visited.insert(path.clone()) {
+                            self.directories_to_walk.push_front((path, depth));
+                        }
+                    } else if metadata.is_file() {
+                        self.actively_walking = Some(paths);
+                        return Some(path);
+                    }
+                }
+            }
+        }
+    }
+}