Fix pg_basebackup so that it accepts 0 as a valid compression level.

The help message for pg_basebackup specifies that the numbers 0 through 9
are accepted as valid values of -Z option. But, previously -Z 0 was rejected
as an invalid compression level.

Per discussion, it's better to make pg_basebackup treat 0 as valid
compression level meaning no compression, like pg_dump.

Back-patch to all supported versions.

Reported-By: Jeff Janes
Reviewed-By: Amit Kapila
Discussion: CAMkU=1x+GwjSayc57v6w87ij6iRGFWt=hVfM0B64b1_bPVKRqg@mail.gmail.com

diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 50ecb685cc615ec27f2765a6291b1cb4fff86820..c76a972a7147fbac4833c148dc7620736b1e0dbe 100644 (file)
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -269,7 +269,7 @@ PostgreSQL documentation
       <listitem>
        <para>
         Enables gzip compression of tar file output, and specifies the
-        compression level (1 through 9, 9 being best
+        compression level (0 through 9, 0 being no compression and 9 being best
         compression). Compression is only available when using the tar
         format.
        </para>

diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index c8c6533ab408aacff8dbc30866a55a4b46629169..1140e766bf0c47570e0dbd0b14771ff4090bdfc2 100644 (file)
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -1404,7 +1404,7 @@ main(int argc, char **argv)
                                break;
                        case 'Z':
                                compresslevel = atoi(optarg);
-                               if (compresslevel <= 0 || compresslevel > 9)
+                               if (compresslevel < 0 || compresslevel > 9)
                                {
                                        fprintf(stderr, _("%s: invalid compression level \"%s\"\n"),
                                                        progname, optarg);