txdb: fix conf calculation.

lib/wallet/txdb.js

@@ -3089,6 +3089,8 @@ function Details(txdb, tx, height) {
   this.wid = this.wallet.wid;
   this.id = this.wallet.id;
 
+  this.chainHeight = height;
+
   this.hash = tx.hash('hex');
   this.tx = tx;
 
@@ -3096,7 +3098,6 @@ function Details(txdb, tx, height) {
   this.height = tx.height;
   this.ts = tx.ts;
   this.index = tx.index;
-  this.confirmations = tx.getConfirmations(height);
 
   this.ps = tx.ps;
 
@@ -3167,6 +3168,20 @@ Details.prototype.setOutput = function setOutput(i, path) {
   }
 };
 
+/**
+ * Calculate confirmations.
+ * @returns {Number}
+ */
+
+Details.prototype.getConfirmations = function getConfirmations() {
+  var depth = this.chainHeight - this.height;
+
+  if (depth < 0)
+    return 0;
+
+  return depth + 1;
+};
+
 /**
  * Calculate fee. Only works if wallet
  * owns all inputs. Returns 0 otherwise.
@@ -3205,6 +3220,7 @@ Details.prototype.toJSON = function toJSON() {
   return {
     wid: this.wid,
     id: this.id,
+    chainHeight: this.chainHeight,
     hash: utils.revHex(this.hash),
     height: this.height,
     block: this.block ? utils.revHex(this.block) : null,
@@ -3212,7 +3228,7 @@ Details.prototype.toJSON = function toJSON() {
     ps: this.ps,
     index: this.index,
     fee: utils.btc(this.getFee()),
-    confirmations: this.confirmations,
+    confirmations: this.getConfirmations(),
     inputs: this.inputs.map(function(input) {
       return input.toJSON(self.network);
     }),