Merge pull request diesel-rs#2239 from weiznich/bugfix/unsanitized_utf8

Fix an utf8 issue

Author: weiznich

diesel/src/pg/connection/raw.rs

@@ -106,7 +106,7 @@ fn last_error_message(conn: *const PGconn) -> String {
     unsafe {
         let error_ptr = PQerrorMessage(conn);
         let bytes = CStr::from_ptr(error_ptr).to_bytes();
-        str::from_utf8_unchecked(bytes).to_string()
+        String::from_utf8_lossy(bytes).to_string()
     }
 }
 

diesel/src/pg/connection/result.rs

@@ -59,6 +59,8 @@ impl<'a> PgResult<'a> {
         unsafe {
             let count_char_ptr = PQcmdTuples(self.internal_result.as_ptr());
             let count_bytes = CStr::from_ptr(count_char_ptr).to_bytes();
+            // Using from_utf8_unchecked is ok here because, we've set the
+            // client encoding to utf8
             let count_str = str::from_utf8_unchecked(count_bytes);
             match count_str {
                 "" => 0,

diesel/src/sqlite/connection/raw.rs

@@ -133,6 +133,7 @@ impl Drop for RawConnection {
 fn convert_to_string_and_free(err_msg: *const libc::c_char) -> String {
     let msg = unsafe {
         let bytes = CStr::from_ptr(err_msg).to_bytes();
+        // sqlite is documented to return utf8 strings here
         str::from_utf8_unchecked(bytes).into()
     };
     unsafe { ffi::sqlite3_free(err_msg as *mut libc::c_void) };

diesel/src/sqlite/connection/sqlite_value.rs

@@ -35,6 +35,8 @@ impl SqliteValue {
             let ptr = ffi::sqlite3_value_text(self.value());
             let len = ffi::sqlite3_value_bytes(self.value());
             let bytes = slice::from_raw_parts(ptr as *const u8, len as usize);
+            // The string is guaranteed to be utf8 according to
+            // https://www.sqlite.org/c3ref/value_blob.html
             str::from_utf8_unchecked(bytes)
         }
     }