reentrancy lock on ensureVault

vault.js

@@ -63,8 +63,13 @@ export async function loginAddress(socket, chainId, address) {
     }
 }
 
+const ensuring = {}
 
 export async function ensureVault(socket, chainId, owner, num) {
+    const key = [chainId, owner, num]
+    if( key in ensuring )
+        return
+    ensuring[key] = true
     console.log('ensureVault', chainId, owner, num)
     if( chainId in chainInfo ) {
         const address = vaultAddress(chainId, owner, num)
@@ -85,6 +90,7 @@ export async function ensureVault(socket, chainId, owner, num) {
             console.log('ensureVault', owner, 'exists:', address)
     }
     await sendVaultInfo(socket, chainId, owner)
+    delete ensuring[key]
 }