Fix zip extraction and bins::infer_bin_dir_template (#869)

- Fix zip extraction code: Ensure dir is rwx and file is readable for curr user
 - Add more integration test for `ExtractedFiles`
 - Fix `bins::infer_bin_dir_template` introduced in #856

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

crates/binstalk-downloader/src/download/extracted_files.rs

@@ -79,14 +79,18 @@ impl ExtractedFiles {
         }
     }
 
-    /// * `path` - must be canonical and must not be empty, but could be "."
-    ///            for top-level.
+    /// * `path` - must be a relative path without `.`, `..`, `/`, `prefix:/`
+    ///            and must not be empty, for these values it is guaranteed to
+    ///            return `None`.
+    ///            But could be set to "." for top-level.
     pub fn get_entry(&self, path: &Path) -> Option<&ExtractedFilesEntry> {
         self.0.get(path)
     }
 
-    /// * `path` - must be canonical and must not be empty, but could be "."
-    ///            for top-level.
+    /// * `path` - must be a relative path without `.`, `..`, `/`, `prefix:/`
+    ///            and must not be empty, for these values it is guaranteed to
+    ///            return `None`.
+    ///            But could be set to "." for top-level.
     pub fn get_dir(&self, path: &Path) -> Option<&HashSet<Box<OsStr>>> {
         match self.get_entry(path)? {
             ExtractedFilesEntry::Dir(file_names) => Some(file_names),
@@ -94,8 +98,10 @@ impl ExtractedFiles {
         }
     }
 
-    /// * `path` - must be canonical and must not be empty, but could be "."
-    ///            for top-level.
+    /// * `path` - must be a relative path without `.`, `..`, `/`, `prefix:/`
+    ///            and must not be empty, for these values it is guaranteed to
+    ///            return `false`.
+    ///            But could be set to "." for top-level.
     pub fn has_file(&self, path: &Path) -> bool {
         matches!(self.get_entry(path), Some(ExtractedFilesEntry::File))
     }

crates/binstalk-downloader/src/download/zip_extraction.rs

@@ -54,17 +54,25 @@ where
     // Get permissions
     let mut perms = None;
 
+    let is_dir = raw_filename.ends_with('/');
+
     #[cfg(unix)]
     {
         use std::{fs::Permissions, os::unix::fs::PermissionsExt};
 
         if let Some(mode) = zip_reader.entry().unix_permissions() {
-            let mode: u16 = mode;
+            // If it is a dir, then it needs to be at least rwx for the current
+            // user so that we can create new files, search for existing files
+            // and list its contents.
+            //
+            // If it is a file, then it needs to be at least readable for the
+            // current user.
+            let mode: u16 = mode | if is_dir { 0o700 } else { 0o400 };
             perms = Some(Permissions::from_mode(mode as u32));
         }
     }
 
-    if raw_filename.ends_with('/') {
+    if is_dir {
         extracted_files.add_dir(&filename);
 
         // This entry is a dir.