Some tests with ident and crlf filters

Fixed the filter order to match core Git, too.

This test demonstrates an interesting behavior of core Git (which
is totally reasonable and which libgit2 matches, although mostly
by coincidence).  If you use the ident filter and commit a file
with a garbage ident in it, like '$Id: this is just garbage$' and
then immediately do a 'git checkout-index' with the new file, Git
will not consider the file out of date and will not overwrite the
file with an updated $Id$.  Libgit2 has the same behavior.  If you
remove the file and then do a checkout-index, it will be replaced
with a filtered version that has injected the OID correctly.

2 files changed, 74 insertions, 2 deletions

diff --git a/tests-clar/checkout/crlf.c b/tests-clar/checkout/crlf.c
index 5f5f1b776..4953609cc 100644
--- a/tests-clar/checkout/crlf.c
+++ b/tests-clar/checkout/crlf.c
@@ -4,6 +4,7 @@
 
 #include "git2/checkout.h"
 #include "repository.h"
+#include "posix.h"
 
 static git_repository *g_repo;
 
@@ -136,3 +137,67 @@ void test_checkout_crlf__autocrlf_true_index_size_is_filtered_size(void)
 
 	git_index_free(index);
 }
+
+void test_checkout_crlf__with_ident(void)
+{
+	git_index *index;
+	git_blob *blob;
+	git_checkout_opts opts = GIT_CHECKOUT_OPTS_INIT;
+	opts.checkout_strategy = GIT_CHECKOUT_SAFE_CREATE;
+
+	cl_git_mkfile("crlf/.gitattributes",
+		"*.txt text\n*.bin binary\n"
+		"*.crlf text eol=crlf\n"
+		"*.lf text eol=lf\n"
+		"*.ident text ident\n"
+		"*.identcrlf ident text eol=crlf\n"
+		"*.identlf ident text eol=lf\n");
+
+	cl_repo_set_bool(g_repo, "core.autocrlf", true);
+
+	/* add files with $Id$ */
+
+	cl_git_mkfile("crlf/lf.ident", ALL_LF_TEXT_RAW "\n$Id: initial content$\n");
+	cl_git_mkfile("crlf/crlf.ident", ALL_CRLF_TEXT_RAW "\r\n$Id$\r\n\r\n");
+
+	cl_git_pass(git_repository_index(&index, g_repo));
+	cl_git_pass(git_index_add_bypath(index, "lf.ident"));
+	cl_git_pass(git_index_add_bypath(index, "crlf.ident"));
+	cl_repo_commit_from_index(NULL, g_repo, NULL, 0, "Some ident files\n");
+
+	git_checkout_head(g_repo, &opts);
+
+	/* check that blob has $Id$ */
+
+	cl_git_pass(git_blob_lookup(&blob, g_repo,
+		& git_index_get_bypath(index, "lf.ident", 0)->oid));
+	cl_assert_equal_s(
+		ALL_LF_TEXT_RAW "\n$Id$\n", git_blob_rawcontent(blob));
+
+	git_blob_free(blob);
+
+	/* check that filesystem is initially untouched - matching core Git */
+
+	cl_assert_equal_file(
+		ALL_LF_TEXT_RAW "\n$Id: initial content$\n", 0, "crlf/lf.ident");
+
+	/* check that forced checkout rewrites correctly */
+
+	p_unlink("crlf/lf.ident");
+	p_unlink("crlf/crlflf.ident");
+
+	git_checkout_head(g_repo, &opts);
+
+	if (GIT_EOL_NATIVE == GIT_EOL_LF)
+		cl_assert_equal_file(
+			ALL_LF_TEXT_RAW
+			"\n$Id: fcf6d4d9c212dc66563b1171b1cd99953c756467$\n",
+			0, "crlf/lf.ident");
+	else
+		cl_assert_equal_file(
+			ALL_LF_TEXT_AS_CRLF
+			"\r\n$Id: fcf6d4d9c212dc66563b1171b1cd99953c756467$\r\n",
+			0, "crlf/lf.ident");
+
+	git_index_free(index);
+}
diff --git a/tests-clar/clar_libgit2.c b/tests-clar/clar_libgit2.c
index 4cf682449..d7e28831f 100644
--- a/tests-clar/clar_libgit2.c
+++ b/tests-clar/clar_libgit2.c
@@ -455,8 +455,15 @@ void clar__assert_equal_file(
 		if (ignore_cr)
 			bytes = strip_cr_from_buf(buf, bytes);
 
-		clar__assert(memcmp(expected_data, buf, bytes) == 0,
-			file, line, "file content mismatch", path, 1);
+		if (memcmp(expected_data, buf, bytes) != 0) {
+			int pos;
+			for (pos = 0; pos < bytes && expected_data[pos] == buf[pos]; ++pos)
+				/* find differing byte offset */;
+			p_snprintf(
+				buf, sizeof(buf), "file content mismatch at byte %d",
+				(int)(total_bytes + pos));
+			clar__fail(file, line, buf, path, 1);
+		}
 
 		expected_data += bytes;
 		total_bytes   += bytes;