From 9cd2435b9a9841255a27a6f6780a125bbd0aeb46 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Sun, 21 Jul 2013 12:58:07 +0000
Subject: [PATCH] Handle replacement into a position past the original member.

We were incorrectly computing where to insert a member if it was replacing
a previous member that was before the insert point.

llvm-svn: 186792
---
 llvm/test/Object/archive-replace-pos.test | 13 +++++++++++++
 llvm/tools/llvm-ar/llvm-ar.cpp            |  4 ++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/llvm/test/Object/archive-replace-pos.test b/llvm/test/Object/archive-replace-pos.test
index 307f0709a796..0ba9b6dd282a 100644
--- a/llvm/test/Object/archive-replace-pos.test
+++ b/llvm/test/Object/archive-replace-pos.test
@@ -11,3 +11,16 @@ RUN: llvm-ar t %t.a | FileCheck %s
 CHECK: .foo
 CHECK-NEXT: .zed
 CHECK-NEXT: .bar
+
+RUN: llvm-ar rc %t.a %t.foo %t.bar
+RUN: llvm-ar t %t.a | FileCheck --check-prefix=CHECK2 %s
+
+CHECK2: .zed
+CHECK2-NEXT: .foo
+CHECK2-NEXT: .bar
+
+RUN: llvm-ar rca %t.foo %t.a %t.zed
+RUN: llvm-ar t %t.a | FileCheck --check-prefix=CHECK3 %s
+CHECK3: .foo
+CHECK3-NEXT: .zed
+CHECK3-NEXT: .bar
diff --git a/llvm/tools/llvm-ar/llvm-ar.cpp b/llvm/tools/llvm-ar/llvm-ar.cpp
index 4ade562ad80a..b1c898613407 100644
--- a/llvm/tools/llvm-ar/llvm-ar.cpp
+++ b/llvm/tools/llvm-ar/llvm-ar.cpp
@@ -458,10 +458,10 @@ computeNewArchiveMembers(ArchiveOperation Operation,
   int InsertPos = -1;
   StringRef PosName = sys::path::filename(RelPos);
   if (OldArchive) {
-    int Pos = 0;
     for (object::Archive::child_iterator I = OldArchive->begin_children(),
                                          E = OldArchive->end_children();
-         I != E; ++I, ++Pos) {
+         I != E; ++I) {
+      int Pos = Ret.size();
       StringRef Name;
       failIfError(I->getName(Name));
       if (Name == PosName) {