From 6be1a126bdadcc84a2d4086e4d4d80b040786230 Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <agruen@linbit.com>
Date: Mon, 30 Jul 2012 16:47:28 +0200
Subject: Try to recognize concatenated git diffs and handle them appropriately

* src/patch.c (main): Remember the "before" SHA1 hashes of git-style patches;
the same patch will always use the same "before" SHA1 for a specific file.
Try to recognize concatenated patches based on that.
* tests/concat-git-diff: New test case.
* tests/Makefile.am (TESTS): Add new test case.
---
 src/patch.c           | 25 +++++++++++++++++++++++++
 tests/Makefile.am     |  1 +
 tests/concat-git-diff | 41 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+)
 create mode 100644 tests/concat-git-diff

diff --git a/src/patch.c b/src/patch.c
index ae6d0b6..2d6443a 100644
--- a/src/patch.c
+++ b/src/patch.c
@@ -245,6 +245,31 @@ main (int argc, char **argv)
 	    }
 	}
 
+      if (pch_git_diff () && ! skip_rest_of_patch && ! inerrno)
+	{
+	  /* Try to recognize concatenated git diffs based on the SHA1 hashes
+	     in the headers.  Will not always succeed for patches that rename
+	     or copy files.  */
+
+	  char const *previous_sha1 = lookup_sha1 (&instat);
+
+	  if (previous_sha1)
+	    {
+	      char const *sha1 = pch_sha1 (reverse);
+
+	      for (; *previous_sha1 && *sha1; previous_sha1++, sha1++)
+		if (*previous_sha1 != *sha1)
+		  break;
+	      if (*previous_sha1 && *sha1)
+		{
+		  output_files (&instat);
+		  update_sha1 (&instat, pch_sha1 (reverse));
+		}
+	    }
+	  else
+	    update_sha1 (&instat, pch_sha1 (reverse));
+	}
+
       if (read_only_behavior != RO_IGNORE
 	  && ! inerrno && ! S_ISLNK (instat.st_mode)
 	  && access (inname, W_OK) != 0)
diff --git a/tests/Makefile.am b/tests/Makefile.am
index fba38b0..02fc6de 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -20,6 +20,7 @@ TESTS = \
 	asymmetric-hunks \
 	backup-prefix-suffix \
 	bad-filenames \
+	concat-git-diff \
 	copy-rename \
 	corrupt-reject-files \
 	create-delete \
diff --git a/tests/concat-git-diff b/tests/concat-git-diff
new file mode 100644
index 0000000..3bc48ed
--- /dev/null
+++ b/tests/concat-git-diff
@@ -0,0 +1,41 @@
+# Copyright (C) 2010-2012 Free Software Foundation, Inc.
+#
+# Copying and distribution of this file, with or without modification,
+# in any medium, are permitted without royalty provided the copyright
+# notice and this notice are preserved.
+
+. $srcdir/test-lib.sh
+
+require_cat
+use_local_patch
+use_tmpdir
+
+# ==============================================================
+
+ncheck 'echo one > f'
+
+cat > concatenated.diff <<EOF
+diff --git a/f b/f
+index 5626abf..f719efd 100644
+--- a/f
++++ b/f
+@@ -1 +1 @@
+-one
++two
+diff --git a/f b/f
+index f719efd..2bdf67a 100644
+--- a/f
++++ b/f
+@@ -1 +1 @@
+-two
++three
+EOF
+
+check 'patch -p1 < concatenated.diff || echo "Status: $?"' <<EOF
+patching file f
+patching file f
+EOF
+
+check 'cat f' <<EOF
+three
+EOF
-- 
cgit v1.2.1