Remove non portable memory allocations and added check to make sure maxRows is > 0 for non-ResultSet queries

Author: cjbj

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## node-oracledb v1.2.0 (DD Mon YYYY)
 
+- Remove non-portable memory allocation for queries that return NULL.
+
+- Added check to make sure maxRows is greater than zero for non-ResultSet queries.
+
 - Fixed AIX-specific REF CURSOR related failures.
 
 - Optimized CLOB memory allocation to account for different database-to-client character set expansions.

src/njs/src/njsConnection.cpp

@@ -1386,6 +1386,13 @@ void Connection::DoDefines ( eBaton* executeBaton, const dpi::MetaData* meta,
   Define *defines = executeBaton->defines = new Define[numCols];
   int csratio = executeBaton->dpiconn->getByteExpansionRatio ();
 
+  // Check for maxRows must be greater than zero in case of non-resultSet
+  if ( executeBaton->maxRows == 0 )
+  {
+    executeBaton->error = NJSMessages::getErrorMsg ( errInvalidmaxRows );
+    return;
+  }
+
   for (unsigned int col = 0; col < numCols; col++)
   {
     switch(meta[col].dbType)
@@ -1431,26 +1438,36 @@ void Connection::DoDefines ( eBaton* executeBaton, const dpi::MetaData* meta,
          * size expansion when data is converted from the DB character set
          * to AL32UTF8
          */
- 
-        defines[col].maxSize   = (meta[col].dbSize) * csratio;
 
-        if ( NJS_SIZE_T_OVERFLOW ( defines[col].maxSize,
-                                       executeBaton->maxRows ) )
-        {
-          executeBaton->error = NJSMessages::getErrorMsg( errResultsTooLarge );
-          return;
-        }
-        else
+        if ( meta[col].dbSize != 0 )
         {
-          defines[col].buf = (char *)malloc( (size_t)defines[col].maxSize*
-                                             executeBaton->maxRows );
-          if( !defines[col].buf )
+          /* dbSize will be zero in case of "select null from dual" and
+           * malloc(0) behaves diffrently on different platforms, so avoiding it
+           */
+          defines[col].maxSize   = (meta[col].dbSize) * csratio;
+  
+          if ( NJS_SIZE_T_OVERFLOW ( defines[col].maxSize,
+                                         executeBaton->maxRows ) )
           {
-            executeBaton->error = NJSMessages::getErrorMsg( 
-                                    errInsufficientMemory );
+            executeBaton->error = NJSMessages::getErrorMsg(
+                                               errResultsTooLarge );
             return;
           }
+          else
+          {
+            defines[col].buf = (char *)malloc( (size_t)defines[col].maxSize*
+                                               executeBaton->maxRows );
+            if( !defines[col].buf )
+            {
+              executeBaton->error = NJSMessages::getErrorMsg( 
+                                      errInsufficientMemory );
+              return;
+            }
+          }
         }
+        /* The null scenario will have indicator as -1, so memory allocation
+         * not required.
+         */
         break;
       case dpi::DpiDate :
       case dpi::DpiTimestamp:

src/njs/src/njsMessages.cpp

@@ -60,6 +60,7 @@ static const char *errMsg[] =
   "NJS-023: concurrent operations on LOB are not allowed",
   "NJS-024: memory allocation failed",
   "NJS-025: overflow when calculating results area size",
+  "NJS-026: maxRows must be greater than zero",
 };
 
 string NJSMessages::getErrorMsg ( NJSErrorType err, ... )

src/njs/src/njsMessages.h

@@ -59,6 +59,7 @@ typedef enum
   errBusyLob,
   errInsufficientMemory,
   errResultsTooLarge,
+  errInvalidmaxRows,
 
   // New ones should be added here
 

test/connection.js

@@ -254,10 +254,8 @@ describe('1. connection.js', function(){
         "SELECT * FROM oracledb_employees", 
         {}, { maxRows: 0 },
         function(err, result){
-          should.not.exist(err);
-          should.exist(result);
-
-          (result.rows).should.have.length(0);
+          should.exist(err);
+          err.message.should.startWith('NJS-026:');
           done();
         }
       );