commit 4554bfdc2859712a763a12e35a4176914fc7c994
author Alexei Zavjalov <alexei.zavjalov@intel.com> Wed Feb 26 17:28:35 2014 +0700
committer Alexei Zavjalov <alexei.zavjalov@intel.com> Thu Feb 27 00:01:00 2014 +0700
tree 6ec9fde68d61fbf5e33955a54755d3e346b38bb5
parent ef2cc5a9c6e508a3e8b24d04ca35f7422f27e112

Incorrect result of compareTo between empty and non-empty strings

Current implementation of the Strings.compareTo() handles the case when
empty string compares to non-empty string in the wrong way.

This patch adds handler for such cases.

Change-Id: I35cc2cfd5141551d6da65748c44b59e64a3f8117
Signed-off-by: Alexei Zavjalov <alexei.zavjalov@intel.com>

runtime/arch/x86/quick_entrypoints_x86.S

diff --git a/runtime/arch/x86/quick_entrypoints_x86.S b/runtime/arch/x86/quick_entrypoints_x86.S
index b1f2275..8683a56 100644
--- a/runtime/arch/x86/quick_entrypoints_x86.S
+++ b/runtime/arch/x86/quick_entrypoints_x86.S
@@ -1307,8 +1307,10 @@
      *   esi: pointer to this string data
      *   edi: pointer to comp string data
      */
+    jecxz .Lkeep_length
     repe cmpsw                    // find nonmatching chars in [%esi] and [%edi], up to length %ecx
     jne .Lnot_equal
+.Lkeep_length:
     POP edi                       // pop callee save reg
     POP esi                       // pop callee save reg
     ret