From e223c895c5472d576c09912166f3c4ab46bbe12b Mon Sep 17 00:00:00 2001
From: Mark Adler <madler@alumni.caltech.edu>
Date: Sun, 29 May 2016 20:52:47 -0700
Subject: [PATCH] Add zlib version for verbose version option.

The consistency of block sync markers depends on zlib 1.2.6 or
later. pigz -vV will display the zlib version linked with pigz.
---
 pigz.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/pigz.c b/pigz.c
index 3765537..c0cc84b 100644
--- a/pigz.c
+++ b/pigz.c
@@ -3990,7 +3990,11 @@ local int option(char *arg)
             case 'R':  g.rsync = 1;  break;
             case 'S':  get = 3;  break;
             case 'T':  g.headis &= ~0xa;  break;
-            case 'V':  fputs(VERSION, stderr);  exit(0);
+            case 'V':
+                fputs(VERSION, stderr);
+                if (g.verbosity > 1)
+                    fprintf(stderr, "zlib %s\n", zlibVersion());
+                exit(0);
             case 'Z':
                 throw(EINVAL, "invalid option: LZW output not supported: %s",
                       bad);