step should not panic when SQLITE_BUSY encountered

this commit only logs the error, but can more refine grained
method should be used.

reference: https://github.com/jgallagher/rusqlite/blob/master/src/row.rs#L43

diesel/Cargo.toml

@@ -25,7 +25,6 @@ time = { version = "0.1", optional = true }
 url = { version = "1.4.0", optional = true }
 uuid = { version = ">=0.2.0, <0.6.0", optional = true, features = ["use_std"] }
 ipnetwork = { version = "0.12.2", optional = true }
-log = "0.3"
 
 [dev-dependencies]
 cfg-if = "0.1.0"

diesel/src/lib.rs

@@ -22,8 +22,6 @@
 #![cfg_attr(all(test, feature = "clippy"), allow(option_unwrap_used, result_unwrap_used))]
 
 extern crate byteorder;
-#[macro_use]
-extern crate log;
 
 #[macro_use]
 mod macros;

diesel/src/sqlite/connection/raw.rs

@@ -13,28 +13,23 @@ pub struct RawConnection {
     pub internal_connection: *mut ffi::sqlite3,
 }
 
+const BUSY_TIMEOUT: i32 = 5000;
+
 impl RawConnection {
     pub fn establish(database_url: &str) -> ConnectionResult<Self> {
         let mut conn_pointer = ptr::null_mut();
         let database_url = try!(CString::new(database_url));
         let connection_status = unsafe {
-            ffi::sqlite3_open(database_url.as_ptr(), &mut conn_pointer)
+            match ffi::sqlite3_open(database_url.as_ptr(), &mut conn_pointer) {
+                ffi::SQLITE_OK => ffi::sqlite3_busy_timeout(conn_pointer, BUSY_TIMEOUT),
+                err_code => err_code,
+            }
         };
 
         match connection_status {
-            ffi::SQLITE_OK => {
-                let r = unsafe {
-                    ffi::sqlite3_busy_timeout(conn_pointer, 5000)
-                };
-
-                if r != ffi::SQLITE_OK {
-                    warn!("sqlite3_busy_timeout error: {:?}", r);
-                }
-
-                Ok(RawConnection {
-                    internal_connection: conn_pointer,
-                })
-            },
+            ffi::SQLITE_OK => Ok(RawConnection {
+                internal_connection: conn_pointer,
+            }),
             err_code => {
                 let message = super::error_message(err_code);
                 Err(ConnectionError::BadConnection(message.into()))

diesel/src/sqlite/connection/stmt.rs

@@ -123,6 +123,8 @@ impl Statement {
         match unsafe { ffi::sqlite3_step(self.inner_statement) } {
             ffi::SQLITE_DONE => None,
             ffi::SQLITE_ROW => Some(SqliteRow::new(self.inner_statement)),
+            // TODO: better error handling
+            ffi::SQLITE_BUSY => None,
             error => panic!("{}", super::error_message(error)),
         }
     }