fix: image not found in README.md while mdbook build

src/errors.rs

@@ -1,5 +1,5 @@
-use thiserror::Error;
 use std::path::PathBuf;
+use thiserror::Error;
 
 #[derive(Error, Debug)]
 pub enum Error {
@@ -42,6 +42,9 @@ pub enum Error {
     #[error(transparent)]
     Io(#[from] std::io::Error),
 
+    #[error(transparent)]
+    AssetOutsideSrcDir(#[from] std::path::StripPrefixError),
+
     #[error(transparent)]
     Book(#[from] mdbook::errors::Error),
     #[error(transparent)]

src/resources/asset.rs

@@ -82,14 +82,7 @@ impl Asset {
             return Err(Error::AssetFile(absolute_location));
         }
         // Use filename as embedded file path with content from absolute_location.
-        let binding = utils::normalize_path(Path::new(link));
-        debug!("Extracting file name from = {:?}, binding = '{binding:?}'", &full_filename.display());
-        let filename = if cfg!(target_os = "windows") {
-            binding.as_os_str().to_os_string()
-                .into_string().expect("Error getting filename for Local Asset").replace('\\', "/")
-        } else {
-            String::from(binding.as_path().to_str().unwrap())
-        };
+        let filename = full_filename.strip_prefix(src_dir)?;
 
         let asset = Asset::new(
             filename,
@@ -112,7 +105,13 @@ impl Asset {
     pub(crate) fn compute_asset_path_by_src_and_link(link: &str, chapter_dir: &PathBuf) -> PathBuf {
         let mut reassigned_asset_root: PathBuf = PathBuf::from(chapter_dir);
         let link_string = String::from(link);
-        // if chapter is a MD file, remove if from path
+        // mdbook built-in link preprocessor have `README.md` renamed and `index.md` is not exist
+        // strip the converted filename in the path 
+        if chapter_dir.ends_with("index.md") && !chapter_dir.exists() {
+            debug!("It seems a `README.md` chapter, adjust the chapter root.");
+            reassigned_asset_root.pop();
+        }
+        // if chapter is a MD file or not exist, remove if from path
         if chapter_dir.is_file() {
             reassigned_asset_root.pop();
         }

src/resources/resource.rs

@@ -48,9 +48,15 @@ pub(crate) fn find(ctx: &RenderContext) -> Result<HashMap<String, Asset>, Error>
                     continue;
                 }
                 for link in find_assets_in_markdown(&ch.content)? {
-                    let asset = match Url::parse(&link) {
-                        Ok(url) => Asset::from_url(url, &ctx.destination),
-                        Err(_) => Asset::from_local(&link, &src_dir, ch.path.as_ref().unwrap()),
+                    let asset = if let Ok(url) = Url::parse(&link) {
+                        Asset::from_url(url, &ctx.destination)
+                    } else {
+                        let result = Asset::from_local(&link, &src_dir, ch.path.as_ref().unwrap());
+                        if let Err(Error::AssetOutsideSrcDir(_)) = result {
+                            warn!("Asset '{link}' is outside source dir '{src_dir:?}' and ignored");
+                            continue;
+                        };
+                        result
                     }?;
 
                     // that is CORRECT generation way

tests/dummy/src/02_advanced/README.md

@@ -0,0 +1,5 @@
+# README.md tests
+
+## image link
+
+![Awesome image in the same folder](Epub_logo.svg "Awesome")

tests/dummy/src/SUMMARY.md

@@ -2,3 +2,7 @@
 
 - [Chapter 1](./chapter_1.md)
   - [Getting started](01_getting_started/02_article.md)
+
+# Advanced
+
+- [README.md tests](./02_advanced/README.md)

tests/integration_tests.rs

@@ -125,17 +125,38 @@ fn look_for_chapter_1_heading() {
     assert!(content.contains("<h1>Chapter 1</h1>"));
 }
 
+#[test]
+#[serial]
+fn look_for_chapter_2_image_link_in_readme() {
+    init_logging();
+    let mut doc = generate_epub().unwrap();
+
+    let path = if cfg!(target_os = "linux") {
+        Path::new("OEBPS").join("02_advanced").join("README.html") // linux
+    } else {
+        Path::new("OEBPS/02_advanced/README.html").to_path_buf() // windows with 'forward slash' /
+    };
+    let content = doc.0.get_resource_str_by_path(path).unwrap();
+
+    assert!(content.contains("<img src=\"Epub_logo.svg\""));
+}
+
 #[test]
 #[serial]
 fn rendered_document_contains_all_chapter_files_and_assets() {
     init_logging();
     debug!("rendered_document_contains_all_chapter_files_and_assets...");
-    let chapters = vec!["chapter_1.html", "rust-logo.png"];
+    let chapters = vec![
+        "chapter_1.html",
+        "rust-logo.png",
+        "02_advanced/README.html",
+        "02_advanced/Epub_logo.svg",
+    ];
     let mut doc = generate_epub().unwrap();
     debug!("Number of internal epub resources = {:?}", doc.0.resources);
     // number of internal epub resources for dummy test book
-    assert_eq!(10, doc.0.resources.len());
-    assert_eq!(2, doc.0.spine.len());
+    assert_eq!(12, doc.0.resources.len());
+    assert_eq!(3, doc.0.spine.len());
     assert_eq!(doc.0.mdata("title").unwrap(), "DummyBook");
     assert_eq!(doc.0.mdata("language").unwrap(), "en");
     debug!(