Add test case for empty file section.

Not supported at the moment.

src/test.rs

@@ -29,6 +29,13 @@ mod tests {
         process_lines("changeLog".to_string(), Box::new(BufReader::new(file)))
     }
 
+    #[test]
+    #[ignore = "Empty file section handling is not implemented"]
+    fn test_empty_file_section() {
+        let file = fs::File::open("test_data/empty_file_section.diff").unwrap();
+        process_lines("mingw".to_string(), Box::new(BufReader::new(file)))
+    }
+
     #[test]
     fn test_parse_args() {
         let config = parse_args(&vec!["asd"]);

test_data/empty_file_section.diff

@@ -0,0 +1,29 @@
+commit 7fd9fd94fb8f23b86578ed86906b8caf0417db82
+Merge: 5fa0f5238b d9589d4051
+Author: REDACTED <REDACTED@REDACTED>
+Date:   Wed Dec 4 23:06:31 2019 +0100
+
+    Sync with 2.22.2
+
+    * maint-2.22: (43 commits)
+      Git 2.22.2
+      Git 2.21.1
+      mingw: sh arguments need quoting in more circumstances
+      mingw: fix quoting of empty arguments for `sh`
+      mingw: use MSYS2 quoting even when spawning shell scripts
+      mingw: detect when MSYS2's sh is to be spawned more robustly
+      t7415: drop v2.20.x-specific work-around
+      Git 2.20.2
+      t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
+      Git 2.19.3
+      Git 2.18.2
+      Git 2.17.3
+      Git 2.16.6
+      test-drop-caches: use `has_dos_drive_prefix()`
+      Git 2.15.4
+      Git 2.14.6
+      mingw: handle `subst`-ed "DOS drives"
+      mingw: refuse to access paths with trailing spaces or periods
+      mingw: refuse to access paths with illegal characters
+      unpack-trees: let merged_entry() pass through do_add_entry()'s errors
+      ...