Merge #19413: refactor: Remove confusing BlockIndex global

fa0dfdf447d5b84a1849dc823d8508463600136a refactor: Remove confusing BlockIndex global (MarcoFalke)

Pull request description:

  The global `::BlockIndex()` is problematic for several reasons:

  * It returns a mutable reference to the block tree, without the appropriate lock annotation (`m_block_index` is guarded by `cs_main`). The current code is fine, but in the future this might lead to accidental races and data corruption.
  * The rpc server shouldn't rely on node globals, but rather a context that is passed in to the RPC method.
  * Tests might want to spin up their own block tree, and thus should also not rely on a single global.

  Fix all issues by removing the global

ACKs for top commit:
  promag:
    Code review ACK fa0dfdf447d5b84a1849dc823d8508463600136a.
  jonatack:
    re-ACK fa0dfdf

Tree-SHA512: 8f158fc5e1c67e73588a21c25677b3fa0fe442313b13ec24b87054806c59607d6ba0c062a865ce3e0ee568706bd0d1faa84febda21aff5bcd65dab172f74c52f

1 files changed, 0 insertions, 6 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index e59dda429c..4871a631dc 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1321,12 +1321,6 @@ bool CChainState::IsInitialBlockDownload() const
 
 static CBlockIndex *pindexBestForkTip = nullptr, *pindexBestForkBase = nullptr;
 
-BlockMap& BlockIndex()
-{
-    LOCK(::cs_main);
-    return g_chainman.m_blockman.m_block_index;
-}
-
 static void AlertNotify(const std::string& strMessage)
 {
     uiInterface.NotifyAlertChanged();