Add a comment mentioning that I/O errors are ignored.

sunfishcode · sunfishcode · commit 5123b2319f7e · 2017-12-07T05:22:34.000-08:00
diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs
@@ -450,6 +450,8 @@ impl Read for File {
     }
 
     fn size_snapshot(&self) -> Option<usize> {
+        // Ignore I/O errors; we're just querying the size and position of an
+        // already-open file in preparation for reading from it.
         if let Ok(meta) = self.metadata() {
             let len = meta.len();
             if let Ok(position) = self.inner.seek(SeekFrom::Current(0)) {

Original file line number	Diff line number	Diff line change
`@@ -450,6 +450,8 @@ impl Read for File {`
`450`	`450`	`}`
`451`	`451`
`452`	`452`	`fn size_snapshot(&self) -> Option<usize> {`
	`453`	`+ // Ignore I/O errors; we're just querying the size and position of an`
	`454`	`+ // already-open file in preparation for reading from it.`
`453`	`455`	`if let Ok(meta) = self.metadata() {`
`454`	`456`	`let len = meta.len();`
`455`	`457`	`if let Ok(position) = self.inner.seek(SeekFrom::Current(0)) {`