Merge branch 'en/rerere-multi-stage-1-fix'

A corner case bugfix in "git rerere" code.

* en/rerere-multi-stage-1-fix:
  rerere: avoid buffer overrun
  t4200: demonstrate rerere segfault on specially crafted merge

diff --cc rerere.c
Simple merge

diff --cc t/t4200-rerere.sh
index 428b3c1e9e85a25dab044ae833bf469158c28057,8da998f661e55c849599c6a0dcb02e43a327f413..55b7750ade1c5fd225f830bbbfcb42938abcbe37
--- 1/t/t4200-rerere.sh
--- 2/t/t4200-rerere.sh
+++ b/t/t4200-rerere.sh
@@@ -577,69 -580,33 +577,98 @@@ test_expect_success 'multiple identica
        count_pre_post 0 0
  '
  
 +test_expect_success 'rerere with unexpected conflict markers does not crash' '
 +      git reset --hard &&
 +
 +      git checkout -b branch-1 master &&
 +      echo "bar" >test &&
 +      git add test &&
 +      git commit -q -m two &&
 +
 +      git reset --hard &&
 +      git checkout -b branch-2 master &&
 +      echo "foo" >test &&
 +      git add test &&
 +      git commit -q -a -m one &&
 +
 +      test_must_fail git merge branch-1 &&
 +      echo "<<<<<<< a" >test &&
 +      git rerere &&
 +
 +      git rerere clear
 +'
 +
 +test_expect_success 'rerere with inner conflict markers' '
 +      git reset --hard &&
 +
 +      git checkout -b A master &&
 +      echo "bar" >test &&
 +      git add test &&
 +      git commit -q -m two &&
 +      echo "baz" >test &&
 +      git add test &&
 +      git commit -q -m three &&
 +
 +      git reset --hard &&
 +      git checkout -b B master &&
 +      echo "foo" >test &&
 +      git add test &&
 +      git commit -q -a -m one &&
 +
 +      test_must_fail git merge A~ &&
 +      git add test &&
 +      git commit -q -m "will solve conflicts later" &&
 +      test_must_fail git merge A &&
 +
 +      echo "resolved" >test &&
 +      git add test &&
 +      git commit -q -m "solved conflict" &&
 +
 +      echo "resolved" >expect &&
 +
 +      git reset --hard HEAD~~ &&
 +      test_must_fail git merge A~ &&
 +      git add test &&
 +      git commit -q -m "will solve conflicts later" &&
 +      test_must_fail git merge A &&
 +      cat test >actual &&
 +      test_cmp expect actual &&
 +
 +      git add test &&
 +      git commit -m "rerere solved conflict" &&
 +      git reset --hard HEAD~ &&
 +      test_must_fail git merge A &&
 +      cat test >actual &&
 +      test_cmp expect actual
 +'
 +
+ test_expect_success 'setup simple stage 1 handling' '
+       test_create_repo stage_1_handling &&
+       (
+               cd stage_1_handling &&
+ 
+               test_seq 1 10 >original &&
+               git add original &&
+               git commit -m original &&
+ 
+               git checkout -b A master &&
+               git mv original A &&
+               git commit -m "rename to A" &&
+ 
+               git checkout -b B master &&
+               git mv original B &&
+               git commit -m "rename to B"
+       )
+ '
+ 
+ test_expect_success 'test simple stage 1 handling' '
+       (
+               cd stage_1_handling &&
+ 
+               git config rerere.enabled true &&
+               git checkout A^0 &&
+               test_must_fail git merge B^0
+       )
+ '
+ 
  test_done