Fix visiting files in /proc/ directory

* src/fileio.c (Finsert_file_contents): Treat regular files whose
size is reported as zero as if they were special files.  (Bug#75569)

1 files changed, 3 insertions, 2 deletions

diff --git a/src/fileio.c b/src/fileio.c
index db7c491e1a1..bf80d71ab59 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -4747,10 +4747,11 @@ by calling `format-decode', which see.  */)
       goto handled;
     }
 
-  if (seekable || !NILP (end))
+  /* Don't believe st.st_size if it is zero.  */
+  if ((regular && st.st_size > 0) || (!regular && seekable) || !NILP (end))
     total = end_offset - beg_offset;
   else
-    /* For a special file, all we can do is guess.  */
+    /* For a special file that is not seekable, all we can do is guess.  */
     total = READ_BUF_SIZE;
 
   if (NILP (visit) && total > 0)