unify DIRTYCONFIG handling in shell and python plugins

The following issues were fixed:
* comparison too broad (e.g. "0" misinterpreted as "true")
* python: comparing string with number (is never equal in python)
* unwanted non-zero exitcode (compound command "&&" as last command in
  shell code block (e.g. "case" or "if" branch))
* access to unset variable (shell style issue)

plugins/bind/bind9_resolver_stats

@@ -72,9 +72,7 @@ if [ "$1" = "config" ]; then
 
 	# If dirty config capability is enabled then fall through
 	# to output the data with the config information.
-	if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-		exit 0
-	fi
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output the stats.

plugins/bind/bind9_server_stats

@@ -69,11 +69,9 @@ if [ "$1" = "config" ]; then
 		echo ${key}.type COUNTER
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output the stats.

plugins/bind/bind9_socket_stats

@@ -67,11 +67,9 @@ if [ "$1" = "config" ]; then
 		echo ${key}.type COUNTER
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output the stats.

plugins/nginx/nginx_error

@@ -156,7 +156,7 @@ case ${1:-} in
   config)
     do_config
     # support "dirty config" capability
-    if [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ]; then do_fetch; fi
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
     ;;
   autoconf)
     do_autoconf

plugins/oracle/oracle_sysstat

@@ -1119,7 +1119,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch

plugins/postgresql/pgbouncer_client_connections

@@ -46,11 +46,9 @@ if [ "$1" = "config" ]; then
 	        echo ${pool}.type GAUGE
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output looks like this:

plugins/postgresql/pgbouncer_maxwait

@@ -46,11 +46,9 @@ if [ "$1" = "config" ]; then
 	        echo ${pool}.type GAUGE
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output looks like this:

plugins/postgresql/pgbouncer_server_connections

@@ -46,11 +46,9 @@ if [ "$1" = "config" ]; then
 	        echo ${pool}.type GAUGE
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output looks like this:

plugins/postgresql/postgresql_active_backends_by_database

@@ -73,9 +73,7 @@ if [ "$1" = "config" ]; then
 
 	# If dirty config capability is enabled then fall through
 	# to output the data with the config information.
-	if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-		exit 0
-	fi
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 while read pool sep backends junk

plugins/solaris/forks

@@ -98,7 +98,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch

plugins/solaris/fsstat_act_

@@ -163,7 +163,7 @@ suggest)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch

plugins/solaris/fsstat_bytes

@@ -160,7 +160,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch

plugins/solaris/interrupts

@@ -118,7 +118,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch

plugins/solaris/io_disk

@@ -334,7 +334,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch

plugins/streaming/packetship_

@@ -108,9 +108,7 @@ if [ "$1" = "config" ]; then
 
 	# If dirty config capability is enabled then fall through
 	# to output the data with the config information.
-	if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-		exit 0
-	fi
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # If there are no pumps then output fake pump1 data and end.

plugins/weather/openweather_

@@ -83,7 +83,7 @@ then
 	EOF
 
 	# Continue if dirty config is enabled
-	[ "$MUNIN_CAP_DIRTYCONFIG" = 1 ] || exit 0
+	[ "${MUNIN_CAP_DIRTYCONFIG:-0}" = 1 ] || exit 0
 fi
 
 TEMP_AVG=$( expr "$OWAPI" : '.*\<temperature value=\"\(.*\)\" min.*/temperature.*' )

plugins/wifi/wireless_channel_occupation_

@@ -135,7 +135,7 @@ elif [ "${1:-}" = "suggest" ]; then
 	done
 elif [ "${1:-}" = "config" ]; then
 	do_config || exit 1
-	[ "${MUNIN_CAP_DIRTYCONFIG:-0}" = 1 ] && do_fetch
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
 else
 	do_fetch
 fi

plugins/wifi/wireless_signal_noise_

@@ -147,7 +147,7 @@ ACTION="${1:-}"
 case "$ACTION" in
 	config)
 		do_config || exit 1
-		[ "${MUNIN_CAP_DIRTYCONFIG:-0}" = 1 ] && do_fetch
+		if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
 		;;
 	autoconf)
 		if [ -z "$(get_wifi_interfaces)" ]; then

plugins/wifi/wireless_signal_ranges_

@@ -138,7 +138,7 @@ ACTION="${1:-}"
 case "$ACTION" in
 	config)
 		do_config || exit 1
-		[ "${MUNIN_CAP_DIRTYCONFIG:-0}" = 1 ] && do_fetch
+		if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
 		;;
 	autoconf)
 		[ -z "$(get_wifi_interfaces)" ] && echo "no (no wifi interfaces found)" && exit 1

plugins/zfs/zfs_arcstats

@@ -351,7 +351,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch

plugins/zfs/zpool_capacity

@@ -257,7 +257,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch

plugins/znc/znc_logs.py

@@ -159,7 +159,7 @@ def emit_config():
     print('graph_period minute')
     graph_order = []
 
-    if 'MUNIN_CAP_DIRTYCONFIG' in os.environ and os.environ['MUNIN_CAP_DIRTYCONFIG'] == 1:
+    if os.getenv('MUNIN_CAP_DIRTYCONFIG') == "1":
         read_data(1)
     else:
         read_data(0)