truncate: process all files when one fails

Should make test truncate/multiple-files.sh pass

src/uu/truncate/src/truncate.rs

@@ -14,6 +14,7 @@ use std::path::Path;
 use uucore::display::Quotable;
 use uucore::error::{FromIo, UResult, USimpleError, UUsageError};
 use uucore::format_usage;
+use uucore::show_if_err;
 use uucore::translate;
 
 use uucore::parser::parse_size::{ParseSizeError, Parser, allow_list_with_all_suffixes};
@@ -284,8 +285,10 @@ fn truncate(
         ));
     }
 
+    // Process every file: a failure on one (e.g. a directory) must not
+    // prevent the remaining files from being truncated.
     for filename in filenames {
-        file_truncate(no_create, reference_size, &mode, filename)?;
+        show_if_err!(file_truncate(no_create, reference_size, &mode, filename));
     }
 
     Ok(())

tests/by-util/test_truncate.rs

@@ -404,6 +404,19 @@ fn test_no_such_dir() {
         .stderr_contains("cannot open 'a/b' for writing: No such file or directory");
 }
 
+/// Test that truncate processes every file even if one fails.
+#[test]
+fn test_continue_after_error() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    at.mkdir("dir");
+    ucmd.args(&["-s", "0", "a", "dir", "b"])
+        .fails()
+        .no_stdout()
+        .stderr_contains("dir");
+    assert!(at.file_exists("a"));
+    assert!(at.file_exists("b"));
+}
+
 /// Test that truncate with a relative size less than 0 is not an error.
 #[test]
 fn test_underflow_relative_size() {