improved pre-OOXML office mime detection

CHANGELOG.md

@@ -10,6 +10,7 @@ Dates are given in YYYY-MM-DD format.
 - Added Text extension set
 - More test coverage
 - Fixed a very minor output bug relating to scanning symlinked directories
+- Better detection for a specific formats (pre-OOXML Office, EXE, DLL)
 
 ### v0.2.11 (2021-04-04)
 #### Features

src/inspectors.rs

@@ -39,7 +39,12 @@ pub fn mime_type<T: MimeDb>(db: &T, path: &Path) -> io::Result<Option<Mime>> {
 		// another is ZIP - many file formats (DOCX, ODT, JAR...) are just ZIP files with particular data structures.
 		// determining that a file is in one of the MS office formats in particular requires looking quite far into the
 		// file.
-		&& mime != &Mime::from_str("application/zip").unwrap());
+		&& mime != &Mime::from_str("application/zip").unwrap()
+		// doc/ppt/xls files are a subset of what's known as an "OLE2 compound document storage", at least according to
+		// shared-mime-info. if a pre-OOXML era MS office file is scanned and identified as x-ole-storage, reading further
+		// will allow it to be detected correctly as the appropriate filetype.
+		&& mime != &Mime::from_str("application/x-ole-storage").unwrap()
+	);
 
 	if r.is_some() {
 		return Ok(r);
@@ -89,6 +94,8 @@ cached! {
 			}
 		}
 
+
+
 		match exts {
 			Some(exts) => {
 				let possible_exts: Vec<String> = exts.iter().map(|e| String::from(*e)).collect();