patch_parse: ensure we can parse a patch

tests/patch/parse.c

+#include "clar_libgit2.h"
+
+#include "patch_common.h"
+
+void test_patch_parse__original_to_change_middle(void)
+{
+	git_patch *patch;
+	const git_diff_delta *delta;
+	char idstr[GIT_OID_HEXSZ+1] = {0};
+
+	cl_git_pass(git_patch_from_patchfile(&patch, PATCH_ORIGINAL_TO_CHANGE_MIDDLE, strlen(PATCH_ORIGINAL_TO_CHANGE_MIDDLE)));
+
+	cl_assert((delta = git_patch_get_delta(patch)) != NULL);
+	cl_assert_equal_i(2, delta->nfiles);
+
+	cl_assert_equal_s(delta->old_file.path, "a/file.txt");
+	cl_assert(delta->old_file.mode == GIT_FILEMODE_BLOB);
+	cl_assert_equal_i(7, delta->old_file.id_abbrev);
+	git_oid_nfmt(idstr, delta->old_file.id_abbrev, &delta->old_file.id);
+	cl_assert_equal_s(idstr, "9432026");
+	cl_assert_equal_i(0, delta->old_file.size);
+
+	cl_assert_equal_s(delta->new_file.path, "b/file.txt");
+	cl_assert(delta->new_file.mode == GIT_FILEMODE_BLOB);
+	cl_assert_equal_i(7, delta->new_file.id_abbrev);
+	git_oid_nfmt(idstr, delta->new_file.id_abbrev, &delta->new_file.id);
+	cl_assert_equal_s(idstr, "cd8fd12");
+	cl_assert_equal_i(0, delta->new_file.size);
+
+	git_patch_free(patch);
+}