mail/exmh2: Adjust MouseWheel scrolling parameters

Units and pages don't mean the same thing they did before.
The number of pixels is in fact a divisor.

- MouseWheel scrolls one line in the Folder Display box (no change).
- MouseWheel scrolls five lines in the message box (no change).
- Shift-MouseWheel scrolls one line (no change).
- Control-MouseWheel scrolls ten lines (changed from a page as
  page doesn't work any more).

mail/exmh2/Makefile

@@ -4,7 +4,7 @@
 
 PORTNAME=	exmh
 PORTVERSION=	2.9.0
-PORTREVISION=	2
+PORTREVISION=	3
 CATEGORIES+=	mail tk
 # XXX: Standard SF fails with a hung download
 MASTER_SITES=	https://sourceforge.net/projects/${PORTNAME}/files/${PORTNAME}/${PORTVERSION}/

mail/exmh2/files/patch-lib_exwin.tcl

@@ -18,11 +18,11 @@
 +    # bind $bindtag <Control-Button-5> [list %W yview scroll 1 pages]
 +    # bind $bindtag <Control-Button-4> [list %W yview scroll -1 pages]
 +
-+    # tcl 8.7a5 and later (units can be pixels/units/pages). See
++    # tcl 8.7a5 and later. See
 +    # https://core.tcl-lang.org/tips/doc/trunk/tip/474.md for more info:
-+    bind $bindtag <MouseWheel> [ list tk::MouseWheel %W y %D -$num units ]
-+    bind $bindtag <Shift-MouseWheel> { tk::MouseWheel %W y %D -1 units }
-+    bind $bindtag <Shift-MouseWheel> { tk::MouseWheel %W y %D -1 pages }
++    bind $bindtag <MouseWheel> [ list tk::MouseWheel %W y %D [ expr 10/-$num ] pixels ]
++    bind $bindtag <Shift-MouseWheel> { tk::MouseWheel %W y %D -10 pixels }
++    bind $bindtag <Control-MouseWheel> { tk::MouseWheel %W y %D -1 pixels }
  }