From 418f5b7692f3e487c875a4b6252e04e8b00a3130 Mon Sep 17 00:00:00 2001
From: Michael Debertol <michael.debertol@gmail.com>
Date: Sat, 31 Jul 2021 20:19:11 +0200
Subject: [PATCH] sort: handle empty merge inputs

---
 src/uu/sort/src/merge.rs      | 14 ++++++++------
 tests/by-util/test_sort.rs    |  9 +++++++++
 tests/fixtures/sort/empty.txt |  0
 3 files changed, 17 insertions(+), 6 deletions(-)
 create mode 100644 tests/fixtures/sort/empty.txt

diff --git a/src/uu/sort/src/merge.rs b/src/uu/sort/src/merge.rs
index 4a45028f7..a5ac9411b 100644
--- a/src/uu/sort/src/merge.rs
+++ b/src/uu/sort/src/merge.rs
@@ -194,12 +194,14 @@ fn merge_without_limit<M: MergeInput + 'static, F: Iterator<Item = M>>(
     let mut mergeable_files = vec![];
 
     for (file_number, receiver) in loaded_receivers.into_iter().enumerate() {
-        mergeable_files.push(MergeableFile {
-            current_chunk: Rc::new(receiver.recv().unwrap()),
-            file_number,
-            line_idx: 0,
-            receiver,
-        })
+        if let Ok(chunk) = receiver.recv() {
+            mergeable_files.push(MergeableFile {
+                current_chunk: Rc::new(chunk),
+                file_number,
+                line_idx: 0,
+                receiver,
+            })
+        }
     }
 
     FileMerger {
diff --git a/tests/by-util/test_sort.rs b/tests/by-util/test_sort.rs
index 36bed4b94..8e9861a39 100644
--- a/tests/by-util/test_sort.rs
+++ b/tests/by-util/test_sort.rs
@@ -1039,3 +1039,12 @@ fn test_output_device() {
         .pipe_in("input")
         .succeeds();
 }
+
+#[test]
+fn test_merge_empty_input() {
+    new_ucmd!()
+        .args(&["-m", "empty.txt"])
+        .succeeds()
+        .no_stderr()
+        .no_stdout();
+}
diff --git a/tests/fixtures/sort/empty.txt b/tests/fixtures/sort/empty.txt
new file mode 100644
index 000000000..e69de29bb