Fix iterator usage bug in CNetFulfilledRequestManager::RemoveAllFulfilledRequests

[Copilot]

Fixed undefined behavior in CNetFulfilledRequestManager::RemoveAllFulfilledRequests() caused by improper iterator usage.

Problem

The function contained this problematic code:

if (it != mapFulfilledRequests.end()) {
    mapFulfilledRequests.erase(it++);  // ❌ Undefined behavior
}

The post-increment operator it++ increments the iterator after passing it to erase(), which causes undefined behavior since:

1. erase() invalidates the iterator
2. The post-increment operation tries to use the invalidated iterator
3. This can lead to crashes or memory corruption

Solution

Changed to the correct pattern:

if (it != mapFulfilledRequests.end()) {
    mapFulfilledRequests.erase(it);  // ✅ Safe and correct
}

Since this function only removes a single element (not iterating in a loop), the post-increment is unnecessary and dangerous.

Impact

• Safety: Eliminates potential crashes in the network request fulfillment system
• Scope: Affects tracking of fulfilled requests from peers (DSQUEUE, DSVIN, etc.)
• Risk: Low-impact fix with no functional changes to behavior

This is a minimal but important fix that ensures the Dash network layer operates safely without iterator-related undefined behavior.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• dash-depends-sources.s3-website-us-west-2.amazonaws.com
  • Triggering command: curl --location --fail --connect-timeout 30 --retry 3 -o /home/REDACTED/work/dash/dash/depends/work/download/gmp-6.3.0/gmp-6.3.0.tar.bz2.temp REDACTED (dns block)
• ftp.gnu.org
  • Triggering command: curl --location --fail --connect-timeout 30 --retry 3 -o /home/REDACTED/work/dash/dash/depends/work/download/gmp-6.3.0/gmp-6.3.0.tar.bz2.temp REDACTED (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

---

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[github-actions]

✅ No Merge Conflicts Detected

This PR currently has no conflicts with other open PRs.