pr: fix a bug whereby --indent=N (-o) did not indent header lines

* src/pr.c (print_header): Honor chars_per_margin also for the header.
Inspired by a patch from C de-Avillez.
This change also adjusts two other %*s directives to be %*.*s instead,
(for the padding on either side of "file_text") to correct a bug that
could make pr print one space of padding instead of none.
* NEWS (Bug fixes): Mention it.
* tests/pr/o3Jml24f-lm-lo: Adjust for new expected output.
* tests/pr/o3a3Sl24f-tn: Likewise.
* tests/pr/o3a3Snl24f-tn: Likewise.
* tests/pr/o3a3l24f-tn: Likewise.
* tests/pr/o3b3Sl24f-tn: Likewise.
* tests/pr/o3b3Snl24f-tn: Likewise.
* tests/pr/o3b3l24f-tn: Likewise.
* tests/pr/o3mSl24f-bl-tn: Likewise.
* tests/pr/o3mSnl24fbltn: Likewise.
* tests/pr/o3ml24f-bl-tn: Likewise.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/pr.c b/src/pr.c
index 0c02430e3..3b6e8015e 100644
--- a/src/pr.c
+++ b/src/pr.c
@@ -2402,8 +2402,10 @@ print_header (void)
   lhs_spaces = available_width >> 1;
   rhs_spaces = available_width - lhs_spaces;
 
-  printf ("\n\n%s%*s%s%*s%s\n\n\n",
-	  date_text, lhs_spaces, " ", file_text, rhs_spaces, " ", page_text);
+  printf ("\n\n%*.*s%s%*.*s%s%*.*s%s\n\n\n",
+          chars_per_margin, chars_per_margin, " ",
+          date_text, lhs_spaces, lhs_spaces, " ",
+          file_text, rhs_spaces, rhs_spaces, " ", page_text);
 
   print_a_header = false;
   output_position = 0;