From 16acb98b6ef427520313120071bedec7022bbc4d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20M=2E=20Bezerra?= <marcospb19@hotmail.com>
Date: Wed, 10 Nov 2021 06:04:31 -0300
Subject: [PATCH] Early return when can't detect extension from magic numbers

---
 src/utils/fs.rs | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/utils/fs.rs b/src/utils/fs.rs
index 86f49d4..6d8856f 100644
--- a/src/utils/fs.rs
+++ b/src/utils/fs.rs
@@ -126,10 +126,16 @@ pub fn try_infer_extension(path: &Path) -> Option<Extension> {
     }
 
     let buf = {
-        let mut b = [0; 270];
-        // Reading errors will just make the inferring fail so its safe to ignore
-        let _ = std::fs::File::open(&path).map(|mut f| std::io::Read::read(&mut f, &mut b));
-        b
+        let mut buf = [0; 270];
+
+        // Error cause will be ignored, so use std::fs instead of fs_err
+        let result = std::fs::File::open(&path).map(|mut file| file.read(&mut buf));
+
+        // In case of file open or read failure, could not infer a extension
+        if result.is_err() {
+            return None;
+        }
+        buf
     };
 
     use crate::extension::CompressionFormat::*;