Changeset 37352

Timestamp:

2023-02-24T14:17:25+13:00 (14 months ago)

Author:

davidb

Message:

STL string and c_str() combination recoded due to compiler error from MacOS gcc/clang. See comment in code for more details

File:

• main/trunk/greenstone2/common-src/indexers/mgpp/jni/MGPPSearchWrapperImpl.cpp (modified) (1 diff)

main/trunk/greenstone2/common-src/indexers/mgpp/jni/MGPPSearchWrapperImpl.cpp

@@ -589 +589 @@
          <<"max docs\t"<<data->queryInfo->maxDocs<<endl<<ends;
 
-  const char *result = output.str().c_str();
-  jstring j_result = j_env->NewStringUTF(result);
-  delete (char *)result;
+  // The following 'one-liner' is determiend by MacOS gcc/clang to be fundamentally
+  // not safe.  This is because it will return a pointer to the cstr inside the string
+  // returned as output.str(), but that string will be destroyed at the end of the method
+  // meaning the 'cstr' is a dangling pointer
+  //
+  // In actual fact, the way we then take a copy of the cstr and put it into j_result
+  // on this occassion means the dangling pointer isn't subsequently used
+  //
+  // However, let's recode to keep everything above board!
+  
+  //const char *result = output.str().c_str();
+  
+  const string result_str = output.str();
+  char* result_cstr = new char [result_str.length()+1];
+  strcpy (result_cstr, result_str.c_str());
+  
+  jstring j_result = j_env->NewStringUTF(result_cstr);
+  delete (char *)result_cstr;
   return j_result;
 }