Merge #15839: [0.18] Revert GetData randomization change (#14897)

8602d8b213 Revert "Change in transaction pull scheduling to prevent InvBlock-related attacks" (Suhas Daftuar)

Pull request description:

  This is for 0.18, not master -- I propose we revert the getdata change for the 0.18 release, rather than try to continue patching it up.  It seems like we've turned up several additional bugs that slipped through initial review (see #15776, #15834), and given the potential severe consequences of these bugs I think it'd make more sense for us to delay releasing this code until 0.19.

  Since the bugfix PRs are getting review, I think we can leave #14897 in master, but we can separately discuss if it should be reverted in master as well if anyone thinks that would be more appropriate.

ACKs for commit 8602d8:

Tree-SHA512: 0389cefc1bc74ac47f87866cf3a4dcfe202740a1baa3db074137e0aa5859672d74a50a34ccdb7cf43b3a3c99ce91e4ba1fb512d04d1d383d4cc184a8ada5543f

1 files changed, 11 insertions, 0 deletions

diff --git a/src/util/time.cpp b/src/util/time.cpp
index c0ede98701..83a7937d8f 100644
--- a/src/util/time.cpp
+++ b/src/util/time.cpp
@@ -97,3 +97,14 @@ std::string FormatISO8601Date(int64_t nTime) {
 #endif
     return strprintf("%04i-%02i-%02i", ts.tm_year + 1900, ts.tm_mon + 1, ts.tm_mday);
 }
+
+std::string FormatISO8601Time(int64_t nTime) {
+    struct tm ts;
+    time_t time_val = nTime;
+#ifdef _MSC_VER
+    gmtime_s(&ts, &time_val);
+#else
+    gmtime_r(&time_val, &ts);
+#endif
+    return strprintf("%02i:%02i:%02iZ", ts.tm_hour, ts.tm_min, ts.tm_sec);
+}