1 files changed, 86 insertions, 0 deletions
diff --git a/libpatch_format_unified_patch.c b/libpatch_format_unified_patch.c
new file mode 100644
index 0000000..1caab9c
--- /dev/null
+++ b/libpatch_format_unified_patch.c
@@ -0,0 +1,86 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+static void
+print_line(struct libpatch_diff2_printer *printer, const struct libpatch_file *file, size_t lineno)
+{
+	printer->put_line(printer, file->lines[lineno]);
+	printer->put_newline(printer);
+	if (lineno + 1 == file->nlines && !file->lf_terminated) {
+		printer->put_no_newline(printer, "\\ No newline at end of file");
+		printer->put_newline(printer);
+	}
+}
+
+
+static void
+print_change(struct libpatch_diff2_printer *printer, int fileno, const struct libpatch_file *file, size_t lineno)
+{
+	printer->put_change_prefix(printer, fileno == 1 ? "-" : "+", fileno, 0, lineno);
+	print_line(printer, file, lineno);
+}
+
+
+static void
+print_context(struct libpatch_diff2_printer *printer, const struct libpatch_file *file, size_t lineno)
+{
+	printer->put_context_prefix(printer, " ", 1, 1, lineno);
+	print_line(printer, file, lineno);
+}
+
+
+int
+libpatch_format_unified_patch(struct libpatch_diff2_printer *printer, struct libpatch_diff2 *diff, size_t difflen,
+                              const struct libpatch_file *file1, const struct libpatch_file *file2)
+{
+	size_t i, j, n, ai, bi, an, bn;
+
+	printer->put_label_prefix(printer, "---", 1);
+	printer->put_whitespace(printer, " ");
+	if (file1->label)
+		printer->put_label(printer, file1->label, 1);
+	printer->put_newline(printer);
+
+	printer->put_label_prefix(printer, "+++", 2);
+	printer->put_whitespace(printer, " ");
+	if (file2->label)
+		printer->put_label(printer, file2->label, 2);
+	printer->put_newline(printer);
+
+	ai = 0;
+	bi = 0;
+	for (i = 0; (n = libpatch_next_hunk(diff, difflen, &i, &ai, &bi, &an, &bn, 0));) {
+		printer->put_hunk_head_prefix(printer, "@@", 0);
+		printer->put_whitespace(printer, " ");
+		printer->put_hunk_start(printer, "-", ai + (size_t)(an > 0), 1);
+		if (an)
+			printer->put_hunk_length(printer, ",", an, 1);
+		printer->put_whitespace(printer, " ");
+		printer->put_hunk_start(printer, "+", bi + (size_t)(bn > 0), 2);
+		if (bn)
+			printer->put_hunk_length(printer, ",", bn, 2);
+		printer->put_whitespace(printer, " ");
+		printer->put_hunk_head_suffix(printer, "@@", 0);
+		printer->put_newline(printer);
+
+		for (n += i; i < n; i++) {
+			for (j = 0; j < diff[i].repetition; j++) {
+				if (diff[i].change == LIBPATCH_DIFF2_FILE1_ONLY) {
+					print_change(printer, 1, file1, ai++);
+				} else if (diff[i].change == LIBPATCH_DIFF2_FILE2_ONLY) {
+					print_change(printer, 2, file2, bi++);
+				} else if (diff[i].change == LIBPATCH_DIFF2_TWO_FILE_CHANGE) {
+					print_change(printer, 1, file1, ai++);
+					print_change(printer, 2, file2, bi++);
+				} else if (printer->use_file2_when_common) {
+					print_context(printer, file2, bi++), ai++;
+				} else {
+					print_context(printer, file1, ai++), bi++;
+				}
+			}
+		}
+	}
+
+	return 0;
+}