Fix integer overflow microsoft#2357

src/io/config.cpp

@@ -307,12 +307,21 @@ void Config::CheckParamConflict() {
   }
   // Check max_depth and num_leaves
   if (max_depth > 0) {
-    int full_num_leaves = static_cast<int>(std::pow(2, max_depth));
+    double full_num_leaves = std::pow(2, max_depth);
     if (full_num_leaves > num_leaves
         && num_leaves == kDefaultNumLeaves) {
       Log::Warning("Accuracy may be bad since you didn't set num_leaves and 2^max_depth > num_leaves");
     }
-    num_leaves = std::min(num_leaves, 2 << max_depth);
+
+    const int MAX_LEAVES = 2 << 16;
+    if (num_leaves > MAX_LEAVES) {
+        Log::Fatal("num_leaves (%d) is larger than maximum allowed leaves (%d)", num_leaves, MAX_LEAVES);
+    }
+
+    if (full_num_leaves < MAX_LEAVES && full_num_leaves < num_leaves) {
+        // Fits in an int, and is more restrictive than the current num_leaves
+        num_leaves = static_cast<int>(full_num_leaves);
+    }
   }
 }