Make blockdir always net specific

The blocks directory is net specific by definition.

Also this prevents the side effect of calling GetBlocksDir(false) in the
non-mainnet environment.

src/init.cpp

@@ -906,7 +906,7 @@ 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()));
     }
 

src/util/system.cpp

@@ -728,18 +728,17 @@ 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.
@@ -755,9 +754,8 @@ 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;
@@ -801,7 +799,6 @@ void ClearDatadirCache()
 
     pathCached = fs::path();
     pathCachedNetSpecific = fs::path();
-    g_blocks_path_cached = fs::path();
     g_blocks_path_cache_net_specific = fs::path();
 }
 

src/util/system.h

@@ -78,7 +78,8 @@ 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);