Sync with v2.2.1

* maint:
  Git 2.2.1
  Git 2.1.4
  Git 2.0.5
  Git 1.9.5
  Git 1.8.5.6
  fsck: complain about NTFS ".git" aliases in trees
  read-cache: optionally disallow NTFS .git variants
  path: add is_ntfs_dotgit() helper
  fsck: complain about HFS+ ".git" aliases in trees
  read-cache: optionally disallow HFS+ .git variants
  utf8: add is_hfs_dotgit() helper
  fsck: notice .git case-insensitively
  t1450: refactor ".", "..", and ".git" fsck tests
  verify_dotfile(): reject .git case-insensitively
  read-tree: add tests for confusing paths like ".." and ".git"
  unpack-trees: propagate errors adding entries to the index

7 files changed, 191 insertions, 5 deletions

diff --git a/Documentation/RelNotes/1.8.5.6.txt b/Documentation/RelNotes/1.8.5.6.txt
new file mode 100644
index 0000000000..92ff92b1e6
--- /dev/null
+++ b/Documentation/RelNotes/1.8.5.6.txt
@@ -0,0 +1,34 @@
+Git v1.8.5.6 Release Notes
+==========================
+
+Fixes since v1.8.5.5
+--------------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/Documentation/RelNotes/1.9.5.txt b/Documentation/RelNotes/1.9.5.txt
new file mode 100644
index 0000000000..8d6ac0cf53
--- /dev/null
+++ b/Documentation/RelNotes/1.9.5.txt
@@ -0,0 +1,34 @@
+Git v1.9.5 Release Notes
+========================
+
+Fixes since v1.9.4
+------------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/Documentation/RelNotes/2.0.5.txt b/Documentation/RelNotes/2.0.5.txt
new file mode 100644
index 0000000000..3a16f697e8
--- /dev/null
+++ b/Documentation/RelNotes/2.0.5.txt
@@ -0,0 +1,34 @@
+Git v2.0.5 Release Notes
+========================
+
+Fixes since v2.0.4
+------------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/Documentation/RelNotes/2.1.4.txt b/Documentation/RelNotes/2.1.4.txt
new file mode 100644
index 0000000000..d16e5f041f
--- /dev/null
+++ b/Documentation/RelNotes/2.1.4.txt
@@ -0,0 +1,34 @@
+Git v2.1.4 Release Notes
+========================
+
+Fixes since v2.1.3
+------------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/Documentation/RelNotes/2.2.1.txt b/Documentation/RelNotes/2.2.1.txt
new file mode 100644
index 0000000000..d5a3cd9e73
--- /dev/null
+++ b/Documentation/RelNotes/2.2.1.txt
@@ -0,0 +1,34 @@
+Git v2.2.1 Release Notes
+========================
+
+Fixes since v2.2
+----------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/Documentation/config.txt b/Documentation/config.txt
index f615a5c354..9335ff2ae2 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -246,6 +246,17 @@ core.precomposeunicode::
 	When false, file names are handled fully transparent by Git,
 	which is backward compatible with older versions of Git.
 
+core.protectHFS::
+	If set to true, do not allow checkout of paths that would
+	be considered equivalent to `.git` on an HFS+ filesystem.
+	Defaults to `true` on Mac OS, and `false` elsewhere.
+
+core.protectNTFS::
+	If set to true, do not allow checkout of paths that would
+	cause problems with the NTFS filesystem, e.g. conflict with
+	8.3 "short" names.
+	Defaults to `true` on Windows, and `false` elsewhere.
+
 core.trustctime::
 	If false, the ctime differences between the index and the
 	working tree are ignored; useful when the inode change time
diff --git a/Documentation/git.txt b/Documentation/git.txt
index dd172548f3..73dc0ad0a0 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -43,40 +43,45 @@ unreleased) version of Git, that is available from the 'master'
 branch of the `git.git` repository.
 Documentation for older releases are available here:
 
-* link:v2.2.0/git.html[documentation for release 2.2]
+* link:v2.2.1/git.html[documentation for release 2.2.1]
 
 * release notes for
+  link:RelNotes/2.2.1.txt[2.2.1],
   link:RelNotes/2.2.0.txt[2.2].
 
-* link:v2.1.3/git.html[documentation for release 2.1.3]
+* link:v2.1.4/git.html[documentation for release 2.1.4]
 
 * release notes for
+  link:RelNotes/2.1.4.txt[2.1.4],
   link:RelNotes/2.1.3.txt[2.1.3],
   link:RelNotes/2.1.2.txt[2.1.2],
   link:RelNotes/2.1.1.txt[2.1.1],
   link:RelNotes/2.1.0.txt[2.1].
 
-* link:v2.0.4/git.html[documentation for release 2.0.4]
+* link:v2.0.5/git.html[documentation for release 2.0.5]
 
 * release notes for
+  link:RelNotes/2.0.5.txt[2.0.5],
   link:RelNotes/2.0.4.txt[2.0.4],
   link:RelNotes/2.0.3.txt[2.0.3],
   link:RelNotes/2.0.2.txt[2.0.2],
   link:RelNotes/2.0.1.txt[2.0.1],
   link:RelNotes/2.0.0.txt[2.0.0].
 
-* link:v1.9.4/git.html[documentation for release 1.9.4]
+* link:v1.9.5/git.html[documentation for release 1.9.5]
 
 * release notes for
+  link:RelNotes/1.9.5.txt[1.9.5],
   link:RelNotes/1.9.4.txt[1.9.4],
   link:RelNotes/1.9.3.txt[1.9.3],
   link:RelNotes/1.9.2.txt[1.9.2],
   link:RelNotes/1.9.1.txt[1.9.1],
   link:RelNotes/1.9.0.txt[1.9.0].
 
-* link:v1.8.5.5/git.html[documentation for release 1.8.5.5]
+* link:v1.8.5.6/git.html[documentation for release 1.8.5.6]
 
 * release notes for
+  link:RelNotes/1.8.5.6.txt[1.8.5.6],
   link:RelNotes/1.8.5.5.txt[1.8.5.5],
   link:RelNotes/1.8.5.4.txt[1.8.5.4],
   link:RelNotes/1.8.5.3.txt[1.8.5.3],