Populating the transaction in the background before the approval window
opens is what makes the displayed object the verified object. It also
fixes the nonce before the user has answered anything, so two
eth_sendTransaction calls populated concurrently took the same nonce
from a node that had seen neither of them broadcast, and the second
could never be sent: its approved nonce is spent, and the only way to
give it a fresh one is to populate it again after the user has read the
old one off the screen.
A second transaction approval is now refused while one is unanswered,
with EIP-1193 code -32002. The refusal happens before anything is
populated — no second nonce is allocated, no window opens — and the slot
is released when the requesting page has its answer. Signature approvals
are not gated; a signature consumes no nonce.
A collision that does happen is now reported for what it is. A broadcast
the node refused for the nonce, and an approval carrying a nonce this
worker has already broadcast (caught before the node is asked at all),
both report that the transaction did not reach the network and to send
it again, instead of the standing broadcast wording that warns it may
have sent. "already known" keeps that ambiguous wording deliberately: a
node that says it has the transaction has it.
Nothing about verification is weakened. The approval still carries the
transaction the screen displayed, and the artifact is still compared
against that object field for field.
Verification compared the signed artifact against the dApp's request object.
For every field the dApp omitted -- normally nonce, gas limit and all the fee
fields, since the popup filled them in -- the number the user actually read on
screen was verified by nothing, and only absolute ceilings stood behind it.
The transaction is now populated in the background before the approval window
opens, and that populated object is both what the popup displays and what the
signed artifact is verified against. Every consequential field becomes an
equality comparison; the ceilings remain as a backstop. Population failing
means no approval and no window, and the error goes to the requesting page --
earlier than before, where the same estimate failed after the password had been
typed.
The account is pinned too: `from` is compared against the address named at
approval time rather than whichever address is active at signing, so switching
accounts mid-flow refuses instead of signing from an account the approval did
not name. The message-signing path had the same defect and gets the same fix.
Nonce selection moves earlier as a consequence; the concurrent-approval case
that follows from it is tracked at #271.
approvalVerify now compares every field of the signed artifact against the
approval, not a subset. Transaction types are allowlisted to 0/1/2 and any
field the module does not check is refused outright, so a future transaction
type cannot smuggle consequential fields past verification -- an EIP-7702
type-4 artifact that delegates the signer's own EOA while matching every
displayed field was accepted before this change. The serialized bytes handed
to broadcastTransaction are compared against the parsed artifact, so the
guarantee covers the bytes that actually go to the node.
Signing failures in the popup are retryable again. To make that safe, an
approval is claimed synchronously before the first await and every path that
resolves or removes one goes through a single chokepoint that refuses a claimed
approval. Without it, closing the approval window, switching the active address
or a late reject would report "User rejected the request." to the dApp while
the broadcast completed -- the user then redoes the transfer at a fresh nonce
and it sends twice.
Failure copy distinguishes the stage reached, so a user is never told to start
again from the site when the first attempt may already have reached the network.
