fixes #187 - out-of-range InsertColumn to throw exception instead of segfaulting

Author: d99kris

CMakeLists.txt

@@ -183,6 +183,7 @@ if(RAPIDCSV_BUILD_TESTS)
   add_unit_test(test097)
   add_unit_test(test098)
   add_unit_test(test099)
+  add_unit_test(test100)
 
   # perf tests
   add_perf_test(ptest001)

src/rapidcsv.h

@@ -2,7 +2,7 @@
  * rapidcsv.h
  *
  * URL:      https://github.com/d99kris/rapidcsv
- * Version:  8.86
+ * Version:  8.87
  *
  * Copyright (C) 2017-2025 Kristofer Berggren
  * All rights reserved.
@@ -852,7 +852,18 @@ namespace rapidcsv
         if (std::distance(mData.begin(), itRow) >= mLabelParams.mColumnNameIdx)
         {
           const size_t rowIdx = static_cast<size_t>(std::distance(mData.begin(), itRow));
-          itRow->insert(itRow->begin() + static_cast<int>(dataColumnIdx), column.at(rowIdx));
+          if (dataColumnIdx <= itRow->size())
+          {
+            itRow->insert(itRow->begin() + static_cast<int>(dataColumnIdx), column.at(rowIdx));
+          }
+          else
+          {
+            const std::string errStr = "column out of range: " +
+              std::to_string(pColumnIdx) + " (on row " +
+              std::to_string(std::distance(mData.begin(), itRow)) +
+              ")";
+            throw std::out_of_range(errStr);
+          }
         }
       }
 

tests/test100.cpp

@@ -0,0 +1,42 @@
+// test100.cpp - exception message inserting column out-of-range
+
+#include <rapidcsv.h>
+#include "unittest.h"
+
+int main()
+{
+  int rv = 0;
+
+  std::string csv =
+    "A,B,C\n"
+    "1,3,9\n"
+    "2,4,16\n"
+  ;
+
+  std::string path = unittest::TempPath();
+  unittest::WriteFile(path, csv);
+
+  try
+  {
+    rapidcsv::Document doc(path);
+
+    // insert at end (append)
+    doc.InsertColumn(3, std::vector<int>({ 1, 2 }), "D");
+
+    // insert at end (append)
+    doc.InsertColumn(4, std::vector<int>({ 3, 4 }), "E");
+
+    // insert out-of-range
+    ExpectExceptionMsg(doc.InsertColumn(6, std::vector<int>({ 5, 6 }), "F"),
+                       std::out_of_range, "column out of range: 6 (on row 0)");
+  }
+  catch (const std::exception& ex)
+  {
+    std::cout << ex.what() << std::endl;
+    rv = 1;
+  }
+
+  unittest::DeleteFile(path);
+
+  return rv;
+}