Fix example conf and improve --cols error check

Author: bulletmark

Makefile

@@ -29,6 +29,8 @@ uninstall:
 check:
 	flake8 libinput-gestures internal internal-test
 	shellcheck $(SHELLCHECK_OPTS) libinput-gestures-setup list-version-hashes
+	vermin -i -q -t 3.4 libinput-gestures
+	vermin -i -q internal internal-test
 
 doc:	$(DOCOUT)
 

libinput-gestures

@@ -218,7 +218,7 @@ class COMMAND_internal(COMMAND):
         opt.add_argument('-w', '--wrap', action='store_true',
                 help='wrap workspaces when switching to/from start/end')
         opt.add_argument('-c', '--cols', type=int,
-                help='number of horizontal columns in virtual desktop grid')
+                help='number of columns in virtual desktop grid, default=1')
         opt.add_argument('--row', type=int, default=0, help=argparse.SUPPRESS)
         opt.add_argument('--col', type=int, default=0, help=argparse.SUPPRESS)
         opt.add_argument('action', choices=self.commands_list,
@@ -232,17 +232,21 @@ class COMMAND_internal(COMMAND):
         if cmdi >= 2:
             if args.row or args.col:
                 opt.error('Legacy "--row" and "--col" not supported')
-            if not args.cols:
+            if args.cols is None:
                 if cmdi < 4:
                     self.cols = 1
                     cmdi -= 2
                 else:
                     opt.error('"--cols" must be specified')
+            elif args.cols < 1:
+                opt.error('"--cols" must be >= 1')
             else:
                 self.cols = args.cols
         else:
             # Convert old legacy/depreciated arguments to new arguments
-            if args.cols:
+            if args.cols is not None:
+                if args.cols < 1:
+                    opt.error('"--cols" must be >= 1')
                 self.cols = args.cols
             elif args.row:
                 cmdi += 2

libinput-gestures.conf

@@ -104,7 +104,7 @@ gesture swipe right	xdotool key alt+Left
 # gesture swipe left	_internal --cols 4 ws_left
 # gesture swipe right	_internal --cols 4 ws_right
 #
-# Example of 12 static workspaces, e.g. using KDE virtual-desktops,
+# Example of 16 static workspaces, e.g. using KDE virtual-desktops,
 # arranged in 4 rows of 4 columns across using swipe up/down/left/right
 # to navigate in fixed planes, and also using swipe
 # left_up/left_down/right_up/right_down to navigate diagonally. You can