(cut_fields): Detect when the input is empty and handle

that special case.  Before `cut -f1 </dev/null' would improperly
output a single newline.  Reported by Phil Richards.

diff --git a/src/cut.c b/src/cut.c
index 549a0e3..a9cd231 100644 (file)
--- a/src/cut.c
+++ b/src/cut.c
@@ -526,10 +526,16 @@ cut_fields (FILE *stream)
   unsigned int field_idx;
   int found_any_selected_field;
   int buffer_first_field;
+  int empty_input;
 
   found_any_selected_field = 0;
   field_idx = 1;
 
+  c = getc (stream);
+  empty_input = (c == EOF);
+  if (c != EOF)
+    ungetc (c, stream);
+
   /* To support the semantics of the -s flag, we may have to buffer
      all of the first field to determine whether it is `delimited.'
      But that is unnecessary if all non-delimited lines must be printed
@@ -577,22 +583,25 @@ cut_fields (FILE *stream)
          ++field_idx;
        }
 
-      if (print_kth (field_idx))
+      if (c != EOF)
        {
-         if (found_any_selected_field)
-           putchar (delim);
-         found_any_selected_field = 1;
-
-         while ((c = getc (stream)) != delim && c != '\n' && c != EOF)
+         if (print_kth (field_idx))
            {
-             putchar (c);
+             if (found_any_selected_field)
+               putchar (delim);
+             found_any_selected_field = 1;
+
+             while ((c = getc (stream)) != delim && c != '\n' && c != EOF)
+               {
+                 putchar (c);
+               }
            }
-       }
-      else
-       {
-         while ((c = getc (stream)) != delim && c != '\n' && c != EOF)
+         else
            {
-             /* Empty.  */
+             while ((c = getc (stream)) != delim && c != '\n' && c != EOF)
+               {
+                 /* Empty.  */
+               }
            }
        }
 
@@ -611,7 +620,7 @@ cut_fields (FILE *stream)
       else if (c == '\n' || c == EOF)
        {
          if (found_any_selected_field
-             || !(suppress_non_delimited && field_idx == 1))
+             || (!empty_input && !(suppress_non_delimited && field_idx == 1)))
            putchar ('\n');
          if (c == EOF)
            break;