From f031513470aede4a0bb6a24c977bb6b2d6d34cd2 Mon Sep 17 00:00:00 2001
From: Peter Johnson <johnson.peter@gmail.com>
Date: Sun, 9 Jul 2023 21:31:58 -0700
Subject: [PATCH] [ntcore] NetworkTable::GetSubTables(): Remove duplicates
 (#5076)

In Java, a set is used. Use a two-stage approach in C++ to achieve the
same result.
---
 ntcore/src/main/native/cpp/networktables/NetworkTable.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp b/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp
index 1f6a7608d5..77b726ad52 100644
--- a/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp
+++ b/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp
@@ -231,8 +231,14 @@ std::vector<std::string> NetworkTable::GetSubTables() const {
     if (end_subtable == std::string_view::npos) {
       continue;
     }
-    keys.emplace_back(wpi::substr(relative_key, 0, end_subtable));
+    auto subTable = wpi::substr(relative_key, 0, end_subtable);
+    if (keys.empty() || keys.back() != subTable) {
+      keys.emplace_back(subTable);
+    }
   }
+  // remove duplicates
+  std::sort(keys.begin(), keys.end());
+  keys.erase(std::unique(keys.begin(), keys.end()), keys.end());
   return keys;
 }