Merge #14409: utils and libraries: Make 'blocksdir' always net specific

e4a0c3547ed886871f8b3d51c6b4ffdb181a8b9c Improve blocksdir functional test. (Hennadii Stepanov)
c3f1821ac788e522e7558e3575150433450dcb8c Make blockdir always net specific (Hennadii Stepanov)

Pull request description:

  The blocks directory is net specific by definition.

  Also this prevents the side effect of calling `GetBlocksDir(false)` in the non-mainnet environment.
  Currently a new node creates an unused `blocks\` directory in the root of the data directory when `-testnet` or `-regtest` is specified.

  Refs:
  - #12653
  - https://github.com/bitcoin/bitcoin/pull/12653#discussion_r174784834 by @laanwj
  - https://github.com/bitcoin/bitcoin/issues/14595#issuecomment-436011186

Tree-SHA512: c9957a68a4a200ebd2010823a56db7e61563afedcb7c9828e86b13f3af2990e07854b622c1f3374756f94574acb3ea32de7d2a399eef6c0623f0e11265155627

3 files changed, 6 insertions, 8 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 679bf80047..e495a68d55 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -930,7 +930,7 @@ bool AppInitParameterInteraction()
 
     // also see: InitParameterInteraction()
 
-    if (!fs::is_directory(GetBlocksDir(false))) {
+    if (!fs::is_directory(GetBlocksDir())) {
         return InitError(strprintf(_("Specified blocks directory \"%s\" does not exist."), gArgs.GetArg("-blocksdir", "").c_str()));
     }
 
diff --git a/src/util/system.cpp b/src/util/system.cpp
index a4bf126900..7f2e9a3114 100644
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -749,18 +749,17 @@ fs::path GetDefaultDataDir()
 #endif
 }
 
-static fs::path g_blocks_path_cached;
 static fs::path g_blocks_path_cache_net_specific;
 static fs::path pathCached;
 static fs::path pathCachedNetSpecific;
 static CCriticalSection csPathCached;
 
-const fs::path &GetBlocksDir(bool fNetSpecific)
+const fs::path &GetBlocksDir()
 {
 
     LOCK(csPathCached);
 
-    fs::path &path = fNetSpecific ? g_blocks_path_cache_net_specific : g_blocks_path_cached;
+    fs::path &path = g_blocks_path_cache_net_specific;
 
     // This can be called during exceptions by LogPrintf(), so we cache the
     // value so we don't have to do memory allocations after that.
@@ -776,9 +775,8 @@ const fs::path &GetBlocksDir(bool fNetSpecific)
     } else {
         path = GetDataDir(false);
     }
-    if (fNetSpecific)
-        path /= BaseParams().DataDir();
 
+    path /= BaseParams().DataDir();
     path /= "blocks";
     fs::create_directories(path);
     return path;
@@ -822,7 +820,6 @@ void ClearDatadirCache()
 
     pathCached = fs::path();
     pathCachedNetSpecific = fs::path();
-    g_blocks_path_cached = fs::path();
     g_blocks_path_cache_net_specific = fs::path();
 }
 
diff --git a/src/util/system.h b/src/util/system.h
index dca32cc6fc..5932e55793 100644
--- a/src/util/system.h
+++ b/src/util/system.h
@@ -79,7 +79,8 @@ void ReleaseDirectoryLocks();
 
 bool TryCreateDirectories(const fs::path& p);
 fs::path GetDefaultDataDir();
-const fs::path &GetBlocksDir(bool fNetSpecific = true);
+// The blocks directory is always net specific.
+const fs::path &GetBlocksDir();
 const fs::path &GetDataDir(bool fNetSpecific = true);
 void ClearDatadirCache();
 fs::path GetConfigFile(const std::string& confPath);