commit 05b5f01fe731ec1197dbb90d6b0c98cd7dd3b465
from: Stefan Sperling <stsp@stsp.name>
date: Mon Sep 21 00:19:39 2020 UTC

fix segfault which occurred with empty input files

commit - 945524ed4b6d392d757bcb026f93717922e64a88
commit + 05b5f01fe731ec1197dbb90d6b0c98cd7dd3b465
blob - d2e422c8e42c1d2acba415753106bfc8ee1086a9
blob + e47921b35f615024740d645645eb9ebc74225ee1
--- lib/diff_main.c
+++ lib/diff_main.c
@@ -307,7 +307,23 @@ void
 diff_data_init_subsection(struct diff_data *d, struct diff_data *parent,
 			  struct diff_atom *from_atom, unsigned int atoms_count)
 {
-	struct diff_atom *last_atom = from_atom + atoms_count - 1;
+	struct diff_atom *last_atom;
+
+	if (atoms_count == 0) {
+		*d = (struct diff_data){
+			.f = NULL,
+			.pos = 0,
+			.data = "",
+			.len = 0,
+			.root = parent->root,
+			.atoms.head = NULL,
+			.atoms.len = atoms_count,
+		};
+
+		return;
+	}
+
+	last_atom = from_atom + atoms_count - 1;
 	*d = (struct diff_data){
 		.f = NULL,
 		.pos = from_atom->pos,
blob - /dev/null
blob + e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 (mode 644)
blob - /dev/null
blob + f70f10e4db19068f79bc43844b49f3eece45c4e8 (mode 644)
--- /dev/null
+++ test/test014.right.txt
@@ -0,0 +1 @@
+A
blob - /dev/null
blob + f70f10e4db19068f79bc43844b49f3eece45c4e8 (mode 644)
--- /dev/null
+++ test/test015.left.txt
@@ -0,0 +1 @@
+A
blob - /dev/null
blob + e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 (mode 644)