# HG changeset patch
# User Antoine Cezar <antoine.cezar@octobus.net>
# Date 2020-07-24 08:34:04
# Node ID 53af26aa5951e91f0fe2080b5270f86959826155
# Parent  10c36ead86f86316b3f7d18429808d7f939abc71

rhg: handle broken pipe error for stderr

Differential Revision: https://phab.mercurial-scm.org/D8871

diff --git a/rust/rhg/src/ui.rs b/rust/rhg/src/ui.rs
--- a/rust/rhg/src/ui.rs
+++ b/rust/rhg/src/ui.rs
@@ -49,7 +49,7 @@ impl Ui {
             .write_all(bytes)
             .or_else(|e| handle_stderr_error(e))?;
 
-        stderr.flush().or_else(|e| Err(UiError::StderrError(e)))
+        stderr.flush().or_else(|e| handle_stderr_error(e))
     }
 }
 
@@ -94,3 +94,13 @@ fn handle_stdout_error(error: io::Error)
 
     Err(UiError::StdoutError(error))
 }
+
+/// Sometimes writing to stderr is not possible.
+fn handle_stderr_error(error: io::Error) -> Result<(), UiError> {
+    // A broken pipe should not result in a error
+    // like with `| head` for example
+    if let ErrorKind::BrokenPipe = error.kind() {
+        return Ok(());
+    }
+    Err(UiError::StdoutError(error))
+}