reduce unnecessary realloc'ing

Change-Id: Ic597814706573576a0ba330a69a7a38aa97e5224
Reviewed-on: https://gerrit.libreoffice.org/23694Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>

io/source/acceptor/acc_socket.cxx

@@ -198,13 +198,12 @@ namespace io_acceptor {
         {
             notifyListeners(this, &_started, callStarted);
 
-            if( aReadBytes.getLength() != nBytesToRead )
+            if( aReadBytes.getLength() < nBytesToRead )
             {
                 aReadBytes.realloc( nBytesToRead );
             }
 
-            sal_Int32 i = 0;
-            i = m_socket.read( aReadBytes.getArray()  , aReadBytes.getLength() );
+            sal_Int32 i = m_socket.read( aReadBytes.getArray()  , aReadBytes.getLength() );
 
             if(i != nBytesToRead)
             {
@@ -220,7 +219,10 @@ namespace io_acceptor {
 
                 throw ioException;
             }
-
+            if( i < aReadBytes.getLength() )
+            {
+                aReadBytes.realloc( i );
+            }
             return i;
         }
         else

io/source/connector/ctr_pipe.cxx

@@ -49,11 +49,16 @@ namespace stoc_connector {
     {
         if( ! m_nStatus )
         {
-            if( aReadBytes.getLength() != nBytesToRead )
+            if( aReadBytes.getLength() < nBytesToRead )
             {
                 aReadBytes.realloc( nBytesToRead );
             }
-            return m_pipe.read( aReadBytes.getArray()  , aReadBytes.getLength() );
+            sal_Int32 n = m_pipe.read( aReadBytes.getArray()  , aReadBytes.getLength() );
+            if( n < aReadBytes.getLength() )
+            {
+                aReadBytes.realloc( n );
+            }
+            return n;
         }
         else {
             throw IOException();

io/source/connector/ctr_socket.cxx

@@ -123,7 +123,7 @@ namespace stoc_connector {
         {
             notifyListeners(this, &_started, callStarted);
 
-            if( aReadBytes.getLength() != nBytesToRead )
+            if( aReadBytes.getLength() < nBytesToRead )
             {
                 aReadBytes.realloc( nBytesToRead );
             }
@@ -143,7 +143,10 @@ namespace stoc_connector {
 
                 throw ioException;
             }
-
+            if( i < aReadBytes.getLength() )
+            {
+                aReadBytes.realloc( i );
+            }
             return i;
         }
         else