pg_basebackup: Fix a couple of recently-introduced bugs.

robertmhaas · robertmhaas · commit dabf63bc9a5b · 2022-01-27T11:05:48.000-05:00
The server expects the compression level to be between 1 and 9, but Z_DEFAULT_COMPRESSION is -1, so we must not try to send that value to the server. Because pg_basebackup's -R option is implemented on the client side, it can't be used in combination with a backup target. Error out if someone tries that, instead of silently ignoring the option. Both issues were reported by Tushar Ahuja; patch by me. Discussion: http://postgr.es/m/CA+TgmoaMwgdx8HxBjF8hmbohVvPL_0H5LqNrSq0uU+7BKp_Q2A@mail.gmail.com
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
@@ -1871,6 +1871,12 @@ BaseBackup(void)
 			exit(1);
 		}
 
+		if (writerecoveryconf)
+		{
+			pg_log_error("recovery configuration cannot be written when a backup target is used");
+			exit(1);
+		}
+
 		AppendPlainCommandOption(&buf, use_new_option_syntax, "TABLESPACE_MAP");
 
 		if ((colon = strchr(backup_target, ':')) == NULL)
@@ -1913,7 +1919,7 @@ BaseBackup(void)
 		}
 		AppendStringCommandOption(&buf, use_new_option_syntax,
 								  "COMPRESSION", compressmethodstr);
-		if (compresslevel != 0)
+		if (compresslevel != 0 && compresslevel != Z_DEFAULT_COMPRESSION)
 			AppendIntegerCommandOption(&buf, use_new_option_syntax,
 									   "COMPRESSION_LEVEL", compresslevel);
 	}

Original file line number	Diff line number	Diff line change
`@@ -1871,6 +1871,12 @@ BaseBackup(void)`
`1871`	`1871`	`exit(1);`
`1872`	`1872`	`}`
`1873`	`1873`
	`1874`	`+ if (writerecoveryconf)`
	`1875`	`+ {`
	`1876`	`+ pg_log_error("recovery configuration cannot be written when a backup target is used");`
	`1877`	`+ exit(1);`
	`1878`	`+ }`
	`1879`	`+`
`1874`	`1880`	`AppendPlainCommandOption(&buf, use_new_option_syntax, "TABLESPACE_MAP");`
`1875`	`1881`
`1876`	`1882`	`if ((colon = strchr(backup_target, ':')) == NULL)`
`@@ -1913,7 +1919,7 @@ BaseBackup(void)`
`1913`	`1919`	`}`
`1914`	`1920`	`AppendStringCommandOption(&buf, use_new_option_syntax,`
`1915`	`1921`	`"COMPRESSION", compressmethodstr);`
`1916`		`- if (compresslevel != 0)`
	`1922`	`+ if (compresslevel != 0 && compresslevel != Z_DEFAULT_COMPRESSION)`
`1917`	`1923`	`AppendIntegerCommandOption(&buf, use_new_option_syntax,`
`1918`	`1924`	`"COMPRESSION_LEVEL", compresslevel);`
`1919`	`1925`	`}`