fix crash by catching tree_magic's panic and handle it gracefully

5 files changed, 56 insertions, 18 deletions

diff --git a/src/fail.rs b/src/fail.rs
index 1abdea7..36a88d4 100644
--- a/src/fail.rs
+++ b/src/fail.rs
@@ -382,7 +382,9 @@ pub enum MimeError {
     #[fail(display = "File access failed! Error: {}", _0)]
     AccessFailed(Box<HError>),
     #[fail(display = "No MIME type found for this file",)]
-    NoMimeFound
+    NoMimeFound,
+    #[fail(display = "Paniced while trying to find MIME type for: {}!", _0)]
+    Panic(String),
 }
 
 impl From<MimeError> for HError {
diff --git a/src/files.rs b/src/files.rs
index 914f16f..d9f4534 100644
--- a/src/files.rs
+++ b/src/files.rs
@@ -961,23 +961,52 @@ impl File {
         Ok((size as u32, unit))
     }
 
-    pub fn get_mime(&self) -> Option<mime_guess::Mime> {
+    // Sadly tree_magic tends to panic (in unwraps a None) when called
+    // with things like pipes, non-existing files. and other stuff. To
+    // prevent it from crashing hunter it's necessary to catch the
+    // panic with a custom panic hook and handle it gracefully by just
+    // doing nothing
+    pub fn get_mime(&self) -> HResult<mime_guess::Mime> {
+        use std::panic;
+        use crate::fail::MimeError;
+
         if let Some(ext) = self.path.extension() {
             let mime = mime_guess::from_ext(&ext.to_string_lossy()).first();
-            mime
-        } else {
-            // Fix crash in tree_magic when called on non-regular file
-            // Also fix crash when a file doesn't exist any more
-            self.meta()
-                .and_then(|meta| {
-                    if meta.is_file() && self.path.exists() {
-                        let mime = tree_magic::from_filepath(&self.path);
-                        mime::Mime::from_str(&mime).ok()
-                    } else { None }
-                })
+            if mime.is_some() {
+                return Ok(mime.unwrap());
+            }
         }
+
+        self.meta()
+            .map(|meta| {
+                // Take and replace panic handler which does nothing
+                let panic_hook = panic::take_hook();
+                panic::set_hook(Box::new(|_| {} ));
+
+                // Catch possible panic caused by tree_magic
+                let mime = panic::catch_unwind(|| {
+                    match meta.is_file() && self.path.exists() {
+                        true => {
+                            let mime = tree_magic::from_filepath(&self.path);
+                            mime::Mime::from_str(&mime).ok()
+                        }
+                        false => None
+                    }
+                });
+
+                // Restore previous panic handler
+                panic::set_hook(panic_hook);
+
+                mime
+            }).unwrap_or(Ok(None))
+              .unwrap_or(None)
+              .ok_or_else(|| {
+                  let file = self.name.clone();
+                  HError::Mime(MimeError::Panic(file))
+              })
     }
 
+
     pub fn is_text(&self) -> bool {
         tree_magic::match_filepath("text/plain", &self.path)
     }
diff --git a/src/preview.rs b/src/preview.rs
index 0b27176..7e4439a 100644
--- a/src/preview.rs
+++ b/src/preview.rs
@@ -381,7 +381,10 @@ impl Previewer {
                     return Ok(preview?);
                 }
 
-                if let Some(mime) = file.get_mime() {
+                if let Some(mime) = file.get_mime()
+                                        .log_and()
+                                        .ok()
+                {
                     let mime_type = mime.type_().as_str();
                     let is_gif = mime.subtype() == "gif";
                     let has_media = core.config().media_available();
diff --git a/src/quick_actions.rs b/src/quick_actions.rs
index 8f7fa24..5a08e0e 100644
--- a/src/quick_actions.rs
+++ b/src/quick_actions.rs
@@ -12,7 +12,7 @@ use std::ffi::OsString;
 use std::str::FromStr;
 
 
-use crate::fail::{HResult, HError, KeyBindError};
+use crate::fail::{HResult, HError, KeyBindError, ErrorLog};
 use crate::widget::{Widget, WidgetCore, Events};
 use crate::foldview::{Foldable, FoldableWidgetExt, ActingExt};
 use crate::listview::ListView;
@@ -432,12 +432,16 @@ impl QuickFiles for Vec<File> {
     fn common_mime(&self) -> Option<Mime> {
         let first_mime = self
             .get(0)?
-            .get_mime();
+            .get_mime()
+            .log_and()
+            .ok();
 
 
         self.iter()
             .fold(first_mime, |common_mime, file| {
-                let cur_mime = file.get_mime();
+                let cur_mime = file.get_mime()
+                                   .log_and()
+                                   .ok();
 
                 if &cur_mime == &common_mime {
                     cur_mime
diff --git a/src/trait_ext.rs b/src/trait_ext.rs
index 90ce6d3..530d1e8 100644
--- a/src/trait_ext.rs
+++ b/src/trait_ext.rs
@@ -43,6 +43,6 @@ impl PathBufMime for PathBuf {
             .map(|mime| {
                 Ok(format!("{}", mime))
             })
-            .ok_or(MimeError::NoMimeFound)?
+            .map_err(|_| MimeError::NoMimeFound)?
     }
 }