Reformat the check list for sender

Author: NicolasDorier

bip-0078.mediawiki

@@ -260,13 +260,14 @@ The sender should check the payjoin proposal before signing it to prevent a mali
 ** Verify that all of sender's inputs from the original PSBT are in the proposal.
 * For each outputs in the proposal:
 ** Verify that no keypaths is in the PSBT output
-** If it is one of the sender's output
-*** If that's the [[#fee-output|fee ouptut]]:
-**** The amount that was substracted from the output's value is less or equal to <code>maxadditionalfeecontribution</code>. Let's call this amount <code>actual contribution</code>.
-**** Make sure the actual contribution is only paying fee: The <code>actual contribution</code> is less or equals to the difference of absolute fee between the payjoin proposal and the original PSBT.
-**** Make sure the actual contribution is only paying for fee incurred by additional inputs: <code>actual contribution</code> is less or equals to <code>originalPSBTFeeRate * vsize(sender_input_type) * (count(original_psbt_inputs) - count(payjoin_proposal_inputs))</code>. (see [[#fee-output|Fee output]] section)
-*** If it is not the fee output:
-**** Make sure the output's value did not changed.
+** If the output is the [[#fee-output|fee ouptut]]:
+*** The amount that was substracted from the output's value is less or equal to <code>maxadditionalfeecontribution</code>. Let's call this amount <code>actual contribution</code>.
+*** Make sure the actual contribution is only paying fee: The <code>actual contribution</code> is less or equals to the difference of absolute fee between the payjoin proposal and the original PSBT.
+*** Make sure the actual contribution is only paying for fee incurred by additional inputs: <code>actual contribution</code> is less or equals to <code>originalPSBTFeeRate * vsize(sender_input_type) * (count(original_psbt_inputs) - count(payjoin_proposal_inputs))</code>. (see [[#fee-output|Fee output]] section)
+** If the output is the payment output and <code>disableoutputsubstitution=</code> is <code>false</code or not specified
+*** Do not make any check
+** Else
+*** Make sure the output's value did not changed.
 ** Verify that all sender's outputs (ie, all outputs except the output actually paid to the receiver) from the original PSBT are in the proposal.
 * Once the proposal is signed, if <code>minfeerate</code> was specified, check that the fee rate of the payjoin transaction is not less than this value.