Merge branch 'jk/for-each-reflog-ent-reverse'

The code that reads the reflog from the newer to the older entries
did not handle an entry that crosses a boundary of block it uses to
read them correctly.

* jk/for-each-reflog-ent-reverse:
  for_each_reflog_ent_reverse: turn leftover check into assertion
  for_each_reflog_ent_reverse: fix newlines on block boundaries

diff --cc refs.c
Simple merge

diff --cc t/t1410-reflog.sh
index 8cf4461,e582c01..779d4e3
--- 1/t/t1410-reflog.sh
--- 2/t/t1410-reflog.sh
+++ b/t/t1410-reflog.sh
@@@ -245,46 -245,34 +245,76 @@@ test_expect_success 'gc.reflogexpire=fa
  
  '
  
 +test_expect_success 'checkout should not delete log for packed ref' '
 +      test $(git reflog master | wc -l) = 4 &&
 +      git branch foo &&
 +      git pack-refs --all &&
 +      git checkout foo &&
 +      test $(git reflog master | wc -l) = 4
 +'
 +
 +test_expect_success 'stale dirs do not cause d/f conflicts (reflogs on)' '
 +      test_when_finished "git branch -d one || git branch -d one/two" &&
 +
 +      git branch one/two master &&
 +      echo "one/two@{0} branch: Created from master" >expect &&
 +      git log -g --format="%gd %gs" one/two >actual &&
 +      test_cmp expect actual &&
 +      git branch -d one/two &&
 +
 +      # now logs/refs/heads/one is a stale directory, but
 +      # we should move it out of the way to create "one" reflog
 +      git branch one master &&
 +      echo "one@{0} branch: Created from master" >expect &&
 +      git log -g --format="%gd %gs" one >actual &&
 +      test_cmp expect actual
 +'
 +
 +test_expect_success 'stale dirs do not cause d/f conflicts (reflogs off)' '
 +      test_when_finished "git branch -d one || git branch -d one/two" &&
 +
 +      git branch one/two master &&
 +      echo "one/two@{0} branch: Created from master" >expect &&
 +      git log -g --format="%gd %gs" one/two >actual &&
 +      test_cmp expect actual &&
 +      git branch -d one/two &&
 +
 +      # same as before, but we only create a reflog for "one" if
 +      # it already exists, which it does not
 +      git -c core.logallrefupdates=false branch one master &&
 +      : >expect &&
 +      git log -g --format="%gd %gs" one >actual &&
 +      test_cmp expect actual
 +'
 +
+ # Triggering the bug detected by this test requires a newline to fall
+ # exactly BUFSIZ-1 bytes from the end of the file. We don't know
+ # what that value is, since it's platform dependent. However, if
+ # we choose some value N, we also catch any D which divides N evenly
+ # (since we will read backwards in chunks of D). So we choose 8K,
+ # which catches glibc (with an 8K BUFSIZ) and *BSD (1K).
+ #
+ # Each line is 114 characters, so we need 75 to still have a few before the
+ # last 8K. The 89-character padding on the final entry lines up our
+ # newline exactly.
+ test_expect_success 'parsing reverse reflogs at BUFSIZ boundaries' '
+       git checkout -b reflogskip &&
+       z38=00000000000000000000000000000000000000 &&
+       ident="abc <xyz> 0000000001 +0000" &&
+       for i in $(test_seq 1 75); do
+               printf "$z38%02d $z38%02d %s\t" $i $(($i+1)) "$ident" &&
+               if test $i = 75; then
+                       for j in $(test_seq 1 89); do
+                               printf X
+                       done
+               else
+                       printf X
+               fi &&
+               printf "\n"
+       done >.git/logs/refs/heads/reflogskip &&
+       git rev-parse reflogskip@{73} >actual &&
+       echo ${z38}03 >expect &&
+       test_cmp expect actual
+ '
+ 
  test_done