util: Add StripRedundantLastElementsOfPath function

Co-authored-by: saibato <saibato.naga@pm.me>
Co-authored-by: MarcoFalke <falke.marco@gmail.com>

Github-Pull: 20080
Rebased-From: b19e88230f0e93e95e883e65376963cb9c36f606

2 files changed, 38 insertions, 0 deletions

diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index 73b37f909f..bba145696c 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -41,6 +41,28 @@ namespace BCLog {
 
 BOOST_FIXTURE_TEST_SUITE(util_tests, BasicTestingSetup)
 
+BOOST_AUTO_TEST_CASE(util_datadir)
+{
+    ClearDatadirCache();
+    const fs::path dd_norm = GetDataDir();
+
+    gArgs.ForceSetArg("-datadir", dd_norm.string() + "/");
+    ClearDatadirCache();
+    BOOST_CHECK_EQUAL(dd_norm, GetDataDir());
+
+    gArgs.ForceSetArg("-datadir", dd_norm.string() + "/.");
+    ClearDatadirCache();
+    BOOST_CHECK_EQUAL(dd_norm, GetDataDir());
+
+    gArgs.ForceSetArg("-datadir", dd_norm.string() + "/./");
+    ClearDatadirCache();
+    BOOST_CHECK_EQUAL(dd_norm, GetDataDir());
+
+    gArgs.ForceSetArg("-datadir", dd_norm.string() + "/.//");
+    ClearDatadirCache();
+    BOOST_CHECK_EQUAL(dd_norm, GetDataDir());
+}
+
 BOOST_AUTO_TEST_CASE(util_criticalsection)
 {
     RecursiveMutex cs;
diff --git a/src/util/system.cpp b/src/util/system.cpp
index b6a7f3926d..320d695470 100644
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -29,6 +29,7 @@
 #endif // __linux__
 
 #include <algorithm>
+#include <cassert>
 #include <fcntl.h>
 #include <sched.h>
 #include <sys/resource.h>
@@ -579,6 +580,19 @@ fs::path GetDefaultDataDir()
 #endif
 }
 
+namespace {
+fs::path StripRedundantLastElementsOfPath(const fs::path& path)
+{
+    auto result = path;
+    while (result.filename().string() == ".") {
+        result = result.parent_path();
+    }
+
+    assert(fs::equivalent(result, path));
+    return result;
+}
+} // namespace
+
 static fs::path g_blocks_path_cache_net_specific;
 static fs::path pathCached;
 static fs::path pathCachedNetSpecific;
@@ -606,6 +620,7 @@ const fs::path &GetBlocksDir()
     path /= BaseParams().DataDir();
     path /= "blocks";
     fs::create_directories(path);
+    path = StripRedundantLastElementsOfPath(path);
     return path;
 }
 
@@ -636,6 +651,7 @@ const fs::path &GetDataDir(bool fNetSpecific)
         fs::create_directories(path / "wallets");
     }
 
+    path = StripRedundantLastElementsOfPath(path);
     return path;
 }