Account for '\0' string terminator in allocated buffers.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index bedc5ba2aec7e32c14ac35294fad6f6e7cac37f1..842c6e87e6be48e09c9835c19d14a757d8c4673b 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -3936,7 +3936,7 @@ static intptr_t ConstructFunctionFullyQualifiedCString(const Function& function,
     ASSERT(chars != NULL);
     *chars = Isolate::Current()->current_zone()->Alloc<char>(reserve_len + 1);
     written = OS::SNPrint(
-        *chars, reserve_len, lib_class_format, library_name, class_name);
+        *chars, reserve_len + 1, lib_class_format, library_name, class_name);
   } else {
     written = ConstructFunctionFullyQualifiedCString(parent,
                                                      chars,
@@ -6933,13 +6933,13 @@ const char* DeoptInfo::ToCString() const {
     return "No DeoptInfo";
   }
   // First compute the buffer size required.
-  intptr_t len = 0;
+  intptr_t len = 1;

[srdjan, 2012/08/06 16:07:19]

Add comment: // Trailing '\0'.

[Kevin Millikin (Google), 2012/08/07 10:07:59]

Done.

   for (intptr_t i = 0; i < Length(); i++) {
     len += OS::SNPrint(NULL, 0, "[%d(%d):%d]",
-        Instruction(i), FromIndex(i), i);
+                       Instruction(i), FromIndex(i), i);
   }
   // Allocate the buffer.
-  char* buffer = Isolate::Current()->current_zone()->Alloc<char>(len + 1);
+  char* buffer = Isolate::Current()->current_zone()->Alloc<char>(len);
   // Layout the fields in the buffer.
   intptr_t index = 0;
   for (intptr_t i = 0; i < Length(); i++) {
@@ -7219,7 +7219,7 @@ uword Code::GetDeoptPcAtNodeId(intptr_t node_id) const {
 
 const char* Code::ToCString() const {
   const char* kFormat = "Code entry:0x%d";
-  intptr_t len = OS::SNPrint(NULL, 0, kFormat, EntryPoint());
+  intptr_t len = OS::SNPrint(NULL, 0, kFormat, EntryPoint()) + 1;
   char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
   OS::SNPrint(chars, len, kFormat, EntryPoint());
   return chars;