Fix generation of signatures from tx confirmations

src/routes/safe/store/actions/processTransaction.js

@@ -31,18 +31,27 @@ export const generateSignaturesFromTxConfirmations = (
 ) => {
   // The constant parts need to be sorted so that the recovered signers are sorted ascending
   // (natural order) by address (not checksummed).
-  let confirmedAdresses = confirmations.map((conf) => conf.owner.address)
+  const confirmationsMap = confirmations.reduce((map, obj) => {
+    map[obj.owner.address] = obj // eslint-disable-line no-param-reassign
+    return map
+  }, {})
 
   if (preApprovingOwner) {
-    confirmedAdresses = confirmedAdresses.push(preApprovingOwner)
+    confirmationsMap[preApprovingOwner] = { owner: preApprovingOwner }
   }
 
   let sigs = '0x'
-  confirmedAdresses.sort().forEach((addr) => {
-    sigs += `000000000000000000000000${addr.replace(
-      '0x',
-      '',
-    )}000000000000000000000000000000000000000000000000000000000000000001`
+  Object.keys(confirmationsMap).sort().forEach((addr) => {
+    const conf = confirmationsMap[addr]
+    if (conf.signature) {
+      sigs += conf.signature.slice(2)
+    } else {
+      // https://gnosis-safe.readthedocs.io/en/latest/contracts/signatures.html#pre-validated-signatures
+      sigs += `000000000000000000000000${addr.replace(
+        '0x',
+        '',
+      )}000000000000000000000000000000000000000000000000000000000000000001`
+    }
   })
   return sigs
 }