Fix: Do not assume a mail file to be valid UTF8

We did assume that the file contained valid UTF8 when reading to `String`.
Now we read to a byte buffer, which removes the (wrong) assumtion.

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>
(cherry picked from commit 9c249dbeea23ce7c12706ee614d42034aacbf8a6)

1 files changed, 12 insertions, 1 deletions

diff --git a/lib/domain/libimagmail/src/util.rs b/lib/domain/libimagmail/src/util.rs
index d16c2fd5..2c43dd6e 100644
--- a/lib/domain/libimagmail/src/util.rs
+++ b/lib/domain/libimagmail/src/util.rs
@@ -18,6 +18,8 @@
 //
 
 use std::path::Path;
+use std::fs::OpenOptions;
+use std::io::Read;
 
 use failure::Error;
 use failure::Fallible as Result;
@@ -35,7 +37,16 @@ use failure::ResultExt;
 /// TODO: Optimize
 ///
 pub(crate) fn get_message_header_at_key<P: AsRef<Path>, K: AsRef<str>>(p: P, k: K) -> Result<String> {
-    ::mailparse::parse_mail(::std::fs::read_to_string(p.as_ref())?.as_bytes())
+    let buffer = {
+        let mut buffer = Vec::with_capacity(4096); // allocate new buffer with 4 KB space
+        OpenOptions::new()
+            .read(true)
+            .open(p.as_ref())?
+            .read_to_end(&mut buffer)?;
+        buffer
+    };
+
+    ::mailparse::parse_mail(&buffer)
         .context(format_err!("Cannot parse Email {}", p.as_ref().display()))?
         .headers
         .into_iter()