Migrating diff to new error handling

Ended up migrating a bunch of upstream functions as well
including vector, attr_file, and odb in order to get this
to work right.

1 files changed, 14 insertions, 0 deletions

diff --git a/src/fileops.h b/src/fileops.h
index ab57b6f38..c2ba8ffc8 100644
--- a/src/fileops.h
+++ b/src/fileops.h
@@ -77,6 +77,20 @@ extern int git_futils_mktmp(git_buf *path_out, const char *filename);
 extern int git_futils_mv_withpath(const char *from, const char *to, const mode_t dirmode);
 
 /**
+ * Open a file readonly and set error if needed
+ */
+GIT_INLINE(int) git_futils_open_ro(const char *path)
+{
+	int fd = p_open(path, O_RDONLY);
+	if (fd < 0) {
+		if (errno == ENOENT)
+			fd = GIT_ENOTFOUND;
+		giterr_set(GITERR_OS, "Failed to open '%s'", path);
+	}
+	return fd;
+}
+
+/**
  * Get the filesize in bytes of a file
  */
 extern git_off_t git_futils_filesize(git_file fd);