fixes #186 - out-of-range RemoveColumn to throw exception instead of segfaulting

Author: d99kris

CMakeLists.txt

@@ -182,6 +182,7 @@ if(RAPIDCSV_BUILD_TESTS)
   add_unit_test(test096)
   add_unit_test(test097)
   add_unit_test(test098)
+  add_unit_test(test099)
 
   # perf tests
   add_perf_test(ptest001)

src/rapidcsv.h

@@ -2,7 +2,7 @@
  * rapidcsv.h
  *
  * URL:      https://github.com/d99kris/rapidcsv
- * Version:  8.85
+ * Version:  8.86
  *
  * Copyright (C) 2017-2025 Kristofer Berggren
  * All rights reserved.
@@ -774,7 +774,18 @@ namespace rapidcsv
       {
         if (std::distance(mData.begin(), itRow) >= mLabelParams.mColumnNameIdx)
         {
-          itRow->erase(itRow->begin() + static_cast<int>(dataColumnIdx));
+          if (dataColumnIdx < itRow->size())
+          {
+            itRow->erase(itRow->begin() + static_cast<int>(dataColumnIdx));
+          }
+          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/test018.cpp

@@ -8,11 +8,11 @@ int main()
   int rv = 0;
 
   std::string csvref =
-    "B,D\n"
-    "4,256\n"
-    "9,6561\n"
-    "16,65536\n"
-    "25,390625\n"
+    "B,C\n"
+    "4,16\n"
+    "9,81\n"
+    "16,256\n"
+    "25,625\n"
   ;
 
   std::string csv =
@@ -30,7 +30,7 @@ int main()
   {
     rapidcsv::Document doc(path);
 
-    doc.RemoveColumn("C");
+    doc.RemoveColumn("D");
     doc.RemoveColumn(0);
 
     doc.Save();

tests/test099.cpp

@@ -0,0 +1,46 @@
+// test099.cpp - exception message removing out-of-range column
+
+#include <rapidcsv.h>
+#include "unittest.h"
+
+int main()
+{
+  int rv = 0;
+
+  std::string csv =
+    "-,A,B,C,D\n"
+    "1,3,9,81,6561\n"
+    "2,4,16,256\n"
+  ;
+
+  std::string path = unittest::TempPath();
+  unittest::WriteFile(path, csv);
+
+  try
+  {
+    rapidcsv::Document doc(path, rapidcsv::LabelParams(0, 0));
+
+    doc.RemoveColumn("A");
+    unittest::ExpectEqual(std::string, doc.GetColumnName(0), "B");
+
+    doc.RemoveColumn(0);
+    unittest::ExpectEqual(std::string, doc.GetColumnName(0), "C");
+
+    // doc has columns C (0) and D (1) now, thus 2 is out of range.
+    ExpectExceptionMsg(doc.RemoveColumn(2), std::out_of_range,
+                       "column out of range: 2 (on row 0)");
+
+    // column D, while existing, has not data on all rows, thus out of range.
+    ExpectExceptionMsg(doc.RemoveColumn("D"), std::out_of_range,
+                       "column out of range: 1 (on row 2)");
+  }
+  catch (const std::exception& ex)
+  {
+    std::cout << ex.what() << std::endl;
+    rv = 1;
+  }
+
+  unittest::DeleteFile(path);
+
+  return rv;
+}