ApplyCommand: convert to git internal format before applying patch

Applying a patch on Windows failed if the patch had the (normal)
single-LF line endings, but the file on disk had the usual Windows
CR-LF line endings.

Git (and JGit) compute diffs on the git-internal blob, i.e., after
CR-LF transformation and clean filtering. Applying patches to files
directly is thus incorrect and may fail if CR-LF settings don't
match, or if clean/smudge filtering is involved.

Change ApplyCommand to run the file content through the check-in
filters before applying the patch, and run the result through the
check-out filters. This makes patch application succeed even if the
patch has single-LFs, but the file has CR-LF and core.autocrlf is
true.

Add tests for various combinations of line endings in the file and in
the patch, and a test to verify the clean/smudge handling.

See also [1].

Running the file though clean/smudge may give strange results with
LFS-managed files. JGit's DiffFormatter has some extra code and
applies the smudge filter again after having run the file through
the check-in filters (CR-LF and clean). So JGit can actually produce
a diff on LFS-managed files using the normal diff machinery. (If it
doesn't run out of memory, that is. After all, LFS is intended for
_large_ files.) How such a diff would be applied with either C git
or JGit is entirely unclear; neither has any code for this special
case. Compare also [2].

Note that C git just doesn't know about LFS and always diffs after
the check-in filter chain, so for LFS files, it'll produce a diff
of the LFS pointers.

[1] https://github.com/git/git/commit/c24f3abac
[2] https://github.com/git-lfs/git-lfs/issues/440

Bug: 571585
Change-Id: I8f71ff26313b5773ff1da612b0938ad2f18751f5
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

14 files changed, 68 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf.patch b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf.patch
new file mode 100644
index 0000000000..01eb0b9510
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf.patch
@@ -0,0 +1,9 @@
+diff --git a/crlf b/crlf
+index 9206ee6..95dd193 100644
+--- a/crlf
++++ b/crlf
+@@ -1,3 +1,3 @@
+ foo
+-fie
++bar
+ fum
diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf2.patch b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf2.patch
new file mode 100644
index 0000000000..5a6210489c
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf2.patch
@@ -0,0 +1,9 @@
+diff --git a/crlf2 b/crlf2
+index 05c1c78..91e246d 100644
+--- a/crlf2
++++ b/crlf2
+@@ -1,3 +1,3 @@
+ foo

+-fie

++bar

+ fum

diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf2_PostImage b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf2_PostImage
new file mode 100644
index 0000000000..91e246d064
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf2_PostImage
@@ -0,0 +1,3 @@
+foo

+bar

+fum

diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf2_PreImage b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf2_PreImage
new file mode 100644
index 0000000000..05c1c782e5
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf2_PreImage
@@ -0,0 +1,3 @@
+foo

+fie

+fum

diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf3.patch b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf3.patch
new file mode 100644
index 0000000000..b155148b3e
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf3.patch
@@ -0,0 +1,8 @@
+diff --git a/crlf3 b/crlf3
+index e69de29..9206ee6 100644
+--- a/crlf3
++++ b/crlf3
+@@ -0,0 +1,3 @@
++foo
++fie
++fum
diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf3_PostImage b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf3_PostImage
new file mode 100644
index 0000000000..05c1c782e5
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf3_PostImage
@@ -0,0 +1,3 @@
+foo

+fie

+fum

diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf3_PreImage b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf3_PreImage
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf3_PreImage
diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf4.patch b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf4.patch
new file mode 100644
index 0000000000..0cf606390a
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf4.patch
@@ -0,0 +1,9 @@
+diff --git a/crlf4 b/crlf4
+new file mode 100644
+index 0000000..9206ee6
+--- /dev/null
++++ b/crlf4
+@@ -0,0 +1,3 @@
++foo
++fie
++fum
diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf4_PostImage b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf4_PostImage
new file mode 100644
index 0000000000..05c1c782e5
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf4_PostImage
@@ -0,0 +1,3 @@
+foo

+fie

+fum

diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf_PostImage b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf_PostImage
new file mode 100644
index 0000000000..91e246d064
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf_PostImage
@@ -0,0 +1,3 @@
+foo

+bar

+fum

diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf_PreImage b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf_PreImage
new file mode 100644
index 0000000000..05c1c782e5
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/crlf_PreImage
@@ -0,0 +1,3 @@
+foo

+fie

+fum

diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/smudgetest.patch b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/smudgetest.patch
new file mode 100644
index 0000000000..ab4d4265a0
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/smudgetest.patch
@@ -0,0 +1,9 @@
+diff --git a/smudgetest b/smudgetest
+index a24d41e..762c4d0 100644
+--- a/smudgetest
++++ b/smudgetest
+@@ -1,3 +1,3 @@
+ PERLE
+-HEBLE
++sprich
+ speak
diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/smudgetest_PostImage b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/smudgetest_PostImage
new file mode 100644
index 0000000000..ad630893df
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/smudgetest_PostImage
@@ -0,0 +1,3 @@
+PARLA
+sprich
+speak
diff --git a/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/smudgetest_PreImage b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/smudgetest_PreImage
new file mode 100644
index 0000000000..9bbd8c763e
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/org/eclipse/jgit/diff/smudgetest_PreImage
@@ -0,0 +1,3 @@
+PARLA
+HABLA
+speak