Merge #12448: Interrupt block generation on shutdown request

0851a75 rpc: Interrupt block generation on shutdown request (João Barbosa)

Pull request description:

  With this simple change, after running `bitcoin-cli -regtest generate 100000`, it is possible to interrupt `bitcoind` cleanly without waiting for the generation to complete.

Tree-SHA512: f0f7cdde242e595cfdaea31ae8bddbc25933621b63f639e813d272c2b00ce2ef52f0c14ae44954ba8c49f0fc846bcc3bfd5419e52b3347a68bb0341ce6b02d26

src/rpc/mining.cpp

@@ -116,7 +116,7 @@ UniValue generateBlocks(std::shared_ptr<CReserveScript> coinbaseScript, int nGen
     }
     unsigned int nExtraNonce = 0;
     UniValue blockHashes(UniValue::VARR);
-    while (nHeight < nHeightEnd)
+    while (nHeight < nHeightEnd && !ShutdownRequested())
     {
         std::unique_ptr<CBlockTemplate> pblocktemplate(BlockAssembler(Params()).CreateNewBlock(coinbaseScript->reserveScript));
         if (!pblocktemplate.get())