Merge pull request rusqlite#854 from mqudsi/document_default_busy_han…

…dler

Improve busy handler documentation

src/busy.rs

@@ -21,6 +21,9 @@ impl Connection {
     /// connection at any given moment. If another busy handler was defined
     /// (using [`busy_handler`](Connection::busy_handler)) prior to calling this routine, that other
     /// busy handler is cleared.
+    ///
+    /// Newly created connections currently have a default busy timeout of 5000ms, but this may be
+    /// subject to change.
     pub fn busy_timeout(&self, timeout: Duration) -> Result<()> {
         let ms: i32 = timeout
             .as_secs()
@@ -33,8 +36,8 @@ impl Connection {
 
     /// Register a callback to handle `SQLITE_BUSY` errors.
     ///
-    /// If the busy callback is `None`, then `SQLITE_BUSY is returned
-    /// immediately upon encountering the lock.` The argument to the busy
+    /// If the busy callback is `None`, then `SQLITE_BUSY` is returned
+    /// immediately upon encountering the lock. The argument to the busy
     /// handler callback is the number of times that the
     /// busy handler has been invoked previously for the
     /// same locking event. If the busy callback returns `false`, then no
@@ -48,6 +51,9 @@ impl Connection {
     /// handler. Note that calling [`busy_timeout()`](Connection::busy_timeout) or evaluating `PRAGMA
     /// busy_timeout=N` will change the busy handler and thus
     /// clear any previously set busy handler.
+    ///
+    /// Newly created connections default to a [`busy_timeout()`](Connection::busy_timeout) handler
+    /// with a timeout of 5000ms, although this is subject to change.
     pub fn busy_handler(&self, callback: Option<fn(i32) -> bool>) -> Result<()> {
         unsafe extern "C" fn busy_handler_callback(p_arg: *mut c_void, count: c_int) -> c_int {
             let handler_fn: fn(i32) -> bool = mem::transmute(p_arg);