sort: Flush BufWriter, don't panic on write errors

src/uu/sort/src/ext_sort.rs

@@ -115,9 +115,9 @@ fn reader_writer<
                     }),
                     settings,
                     output,
-                );
+                )?;
             } else {
-                print_sorted(chunk.lines().iter(), settings, output);
+                print_sorted(chunk.lines().iter(), settings, output)?;
             }
         }
         ReadResult::SortedTwoChunks([a, b]) => {
@@ -138,9 +138,9 @@ fn reader_writer<
                         .map(|(line, _)| line),
                     settings,
                     output,
-                );
+                )?;
             } else {
-                print_sorted(merged_iter.map(|(line, _)| line), settings, output);
+                print_sorted(merged_iter.map(|(line, _)| line), settings, output)?;
             }
         }
         ReadResult::EmptyInput => {

src/uu/sort/src/merge.rs

@@ -25,7 +25,7 @@ use std::{
 };
 
 use compare::Compare;
-use uucore::error::UResult;
+use uucore::error::{FromIo, UResult};
 
 use crate::{
     GlobalSettings, Output, SortError,
@@ -278,12 +278,19 @@ impl FileMerger<'_> {
     }
 
     fn write_all_to(mut self, settings: &GlobalSettings, out: &mut impl Write) -> UResult<()> {
-        while self.write_next(settings, out) {}
+        while self
+            .write_next(settings, out)
+            .map_err_context(|| "write failed".into())?
+        {}
         drop(self.request_sender);
         self.reader_join_handle.join().unwrap()
     }
 
-    fn write_next(&mut self, settings: &GlobalSettings, out: &mut impl Write) -> bool {
+    fn write_next(
+        &mut self,
+        settings: &GlobalSettings,
+        out: &mut impl Write,
+    ) -> std::io::Result<bool> {
         if let Some(file) = self.heap.peek() {
             let prev = self.prev.replace(PreviousLine {
                 chunk: file.current_chunk.clone(),
@@ -303,12 +310,12 @@ impl FileMerger<'_> {
                             file.current_chunk.line_data(),
                         );
                         if cmp == Ordering::Equal {
-                            return;
+                            return Ok(());
                         }
                     }
                 }
-                current_line.print(out, settings);
+                current_line.print(out, settings)
-            });
+            })?;
 
             let was_last_line_for_file = file.current_chunk.lines().len() == file.line_idx + 1;
 
@@ -335,7 +342,7 @@ impl FileMerger<'_> {
                 }
             }
         }
-        !self.heap.is_empty()
+        Ok(!self.heap.is_empty())
     }
 }
 

src/uu/sort/src/sort.rs

@@ -42,7 +42,7 @@ use std::str::Utf8Error;
 use thiserror::Error;
 use unicode_width::UnicodeWidthStr;
 use uucore::display::Quotable;
-use uucore::error::strip_errno;
+use uucore::error::{FromIo, strip_errno};
 use uucore::error::{UError, UResult, USimpleError, UUsageError, set_exit_code};
 use uucore::line_ending::LineEnding;
 use uucore::parse_size::{ParseSizeError, Parser};
@@ -481,13 +481,14 @@ impl<'a> Line<'a> {
         Self { line, index }
     }
 
-    fn print(&self, writer: &mut impl Write, settings: &GlobalSettings) {
+    fn print(&self, writer: &mut impl Write, settings: &GlobalSettings) -> std::io::Result<()> {
         if settings.debug {
-            self.print_debug(settings, writer).unwrap();
+            self.print_debug(settings, writer)?;
         } else {
-            writer.write_all(self.line.as_bytes()).unwrap();
+            writer.write_all(self.line.as_bytes())?;
-            writer.write_all(&[settings.line_ending.into()]).unwrap();
+            writer.write_all(&[settings.line_ending.into()])?;
         }
+        Ok(())
     }
 
     /// Writes indicators for the selections this line matched. The original line content is NOT expected
@@ -1827,11 +1828,19 @@ fn print_sorted<'a, T: Iterator<Item = &'a Line<'a>>>(
     iter: T,
     settings: &GlobalSettings,
     output: Output,
-) {
+) -> UResult<()> {
+    let output_name = output
+        .as_output_name()
+        .unwrap_or("standard output")
+        .to_owned();
+    let ctx = || format!("write failed: {}", output_name.maybe_quote());
+
     let mut writer = output.into_write();
     for line in iter {
-        line.print(&mut writer, settings);
+        line.print(&mut writer, settings).map_err_context(ctx)?;
     }
+    writer.flush().map_err_context(ctx)?;
+    Ok(())
 }
 
 fn open(path: impl AsRef<OsStr>) -> UResult<Box<dyn Read + Send>> {

tests/by-util/test_sort.rs

@@ -1336,3 +1336,13 @@ fn test_human_blocks_r_and_q() {
 fn test_args_check_conflict() {
     new_ucmd!().arg("-c").arg("-C").fails();
 }
+
+#[cfg(target_os = "linux")]
+#[test]
+fn test_failed_write_is_reported() {
+    new_ucmd!()
+        .pipe_in("hello")
+        .set_stdout(std::fs::File::create("/dev/full").unwrap())
+        .fails()
+        .stderr_is("sort: write failed: 'standard output': No space left on device\n");
+}