svn commit: r1355198 - /thrift/trunk/lib/rb/ext/memory_buffer.c

[bryanduxbury]

Author: bryanduxbury
Date: Fri Jun 29 00:21:19 2012
New Revision: 1355198

URL: http://svn.apache.org/viewvc?rev=1355198&view=rev
Log:
THRIFT-1632. rb: ruby: data corruption in thrift_native implementation of 
MemoryBufferTransport

This patch fixes a subtle bug whereby the read buffer was being resized but the 
method continued to read from the original, unresized buffer but at the wrong 
location.


Modified:
    thrift/trunk/lib/rb/ext/memory_buffer.c

Modified: thrift/trunk/lib/rb/ext/memory_buffer.c
URL: 
http://svn.apache.org/viewvc/thrift/trunk/lib/rb/ext/memory_buffer.c?rev=1355198&r1=1355197&r2=1355198&view=diff
==============================================================================
--- thrift/trunk/lib/rb/ext/memory_buffer.c (original)
+++ thrift/trunk/lib/rb/ext/memory_buffer.c Fri Jun 29 00:21:19 2012
@@ -93,25 +93,26 @@ VALUE rb_thrift_memory_buffer_read_into_
   int index;
   VALUE buf = GET_BUF(self);
 
+  index = FIX2INT(rb_ivar_get(self, index_ivar_id));
   while (i < size) {
-    index = FIX2INT(rb_ivar_get(self, index_ivar_id));
     if (index >= RSTRING_LEN(buf)) {
       rb_raise(rb_eEOFError, "Not enough bytes remain in memory buffer");
     }
     char byte = RSTRING_PTR(buf)[index++];
 
-    if (index >= GARBAGE_BUFFER_SIZE) {
-      rb_ivar_set(self, buf_ivar_id, rb_funcall(buf, slice_method_id, 2, 
INT2FIX(index), INT2FIX(RSTRING_LEN(buf) - 1)));
-      index = 0;
-    }
-    rb_ivar_set(self, index_ivar_id, INT2FIX(index));
-
     if (i >= RSTRING_LEN(buffer_value)) {
       rb_raise(rb_eIndexError, "index %d out of string", i);
     }
     ((char*)RSTRING_PTR(buffer_value))[i] = byte;
     i++;
   }
+
+  if (index >= GARBAGE_BUFFER_SIZE) {
+    rb_ivar_set(self, buf_ivar_id, rb_funcall(buf, slice_method_id, 2, 
INT2FIX(index), INT2FIX(RSTRING_LEN(buf) - 1)));
+    index = 0;
+  }
+  rb_ivar_set(self, index_ivar_id, INT2FIX(index));
+
   return INT2FIX(i);
 }