user72125: So I have an offline wallet created with Electrum. When signing transactions on the cold storage machine, I would like to be able to check that the address I'm sending the change to is actually a change address I own, however since Electrum is offline it's not up-to-date with which addresses have been used, and so the next change address that is used in the transaction hasn't actually been created yet.
For receiving addresses, I was able to manually create these addresses by running:
>> wallet.storage.put('gap_limit', 50)
>> wallet.storage.write()

in the console, which generates 50 rx addresses worth of keys.
However, this only generates receiving addresses, and I have funds in change addresses beyond the 6 that are generated by default. Unfortunately I haven't found how to increase this gap limit for change addresses. I've tried looking through the electrum source but haven't found anything that would let me change this.

user72125: I found that in Electrum, you can create additional change addresses by using the console and typing:
for i in range(0, 100): print(wallet.create_new_address(True))

where 100 is the number of change addresses to create. The True means a change addresses is created, while False creates a standard receiving address. The problem is solved now :)

72125: <p>So I have an offline wallet created with Electrum. When signing transactions on the cold storage machine, I would like to be able to check that the address I'm sending the change to is actually a change address I own, however since Electrum is offline it's not up-to-date with which addresses have been used, and so the next change address that is used in the transaction hasn't actually been created yet.</p>

<p>For receiving addresses, I was able to manually create these addresses by running:</p>

<pre><code>&gt;&gt; wallet.storage.put('gap_limit', 50)
&gt;&gt; wallet.storage.write()
</code></pre>

<p>in the console, which generates 50 rx addresses worth of keys.</p>

<p>However, this only generates <em>receiving</em> addresses, and I have funds in change addresses beyond the 6 that are generated by default. Unfortunately I haven't found how to increase this gap limit for change addresses. I've tried looking through the electrum source but haven't found anything that would let me change this.</p>
 72125: <p>I found that in Electrum, you can create additional change addresses by using the console and typing:</p>
<pre><code>for i in range(0, 100): print(wallet.create_new_address(True))
</code></pre>
<p>where 100 is the number of change addresses to create. The <code>True</code> means a change addresses is created, while <code>False</code> creates a standard receiving address. The problem is solved now :)</p>
