fix rescan crash: shutdown old lightclient before overwriting

RELEASE_NOTES_v1.1.1.md

@@ -14,5 +14,5 @@
 
 | File | SHA-256 |
 |---|---|
-| `SilentDragonXLite` (Linux) | `17b34e63bce97dcb53eb930b6766aca88c7388303cc34db57d11db96afae5f48` |
-| `SilentDragonXLite.exe` (Windows) | `ce2df9860927a07459ef50231e4c133a07a96891b668e90187849492f96ec125` |
+| `SilentDragonXLite` (Linux) | `bc5e0020d784a905e2d461ccb5b4c5da4436072245370ec9e09a17e9e7ad0307` |
+| `SilentDragonXLite.exe` (Windows) | `47f45ff44521eb46ee87189ee2318d0ca61f44b39c2a9d875e1a3d7329700df8` |

lib/src/lib.rs

@@ -140,6 +140,17 @@ pub extern "C" fn litelib_initialize_new_from_phrase(dangerous: bool, server: *c
 
     //println!("Initializing with server: {}, seed: {}", server_str, seed_str);
 
+    // Shut down the existing client if one is running, to stop background threads
+    if overwrite {
+        let old_lc = match LIGHTCLIENT.lock() {
+            Ok(l) => l.borrow().clone(),
+            Err(poisoned) => poisoned.into_inner().borrow().clone(),
+        };
+        if let Some(lc) = old_lc {
+            lc.shutdown();
+        }
+    }
+
     let server = LightClientConfig::get_server_or_default(Some(server_str));
     let (config, _latest_block_height) = match LightClientConfig::create(server, dangerous) {
         Ok((c, h)) => {