Fix same variant set multiple times during EMS

Update extra match search mechanism when one variant is specified
several time in search query. Apply same behavior than for extra
specifier: all values specified act as an AND operation. For instance
"foo=val1 foo=val2" now returns modules that define a foo variant where
val1 and val2 are both values available.

Specification is only adapted for search context. On selection context
only last value is retained when same variant is set several times.

Fixes #499

Author: xdelaruelle

tcl/modscan.tcl

@@ -232,20 +232,15 @@ proc doesModVariantMatch {mod pvrlist} {
          set availvrarr([lindex $availvr 0]) [lindex $availvr 1]
          set availvrisbool([lindex $availvr 0]) [lindex $availvr 4]
       }
-      foreach pvr $pvrlist {
-         set pvrarr([lindex $pvr 0]) [lindex $pvr 1]
-         set pvrisbool([lindex $pvr 0]) [lindex $pvr 2]
-      }
-
       # no match if a specified variant is not found among module variants or
       # if the value is not available
-      foreach vrname [array names pvrarr] {
+      foreach pvr $pvrlist {
+         lassign $pvr vrname pvrval pvrisbool
          # if variant is a boolean, specified value should be a boolean too
          # any value accepted for free-value variant
          if {![info exists availvrarr($vrname)] || ($availvrisbool($vrname)\
-            && !$pvrisbool($vrname)) || (!$availvrisbool($vrname) && [llength\
-            $availvrarr($vrname)] > 0 && $pvrarr($vrname) ni\
-            $availvrarr($vrname))} {
+            && !$pvrisbool) || (!$availvrisbool($vrname) && [llength\
+            $availvrarr($vrname)] > 0 && $pvrval ni $availvrarr($vrname))} {
             set ret 0
             break
          }

tcl/modspec.tcl

@@ -1431,8 +1431,10 @@ proc parseModuleSpecificationProcAdvVersSpec {mlspec nonamespec xtspec\
                if {[string last = $curarg] != $vrsepidx} {
                   knerror "Invalid variant specification '$arg'"
                }
-               # replace previous value for variant if already set
-               if {[info exists vrnamearr($vrname)]} {
+               # replace previous value for variant if already set unless if
+               # extra specifier search enabled where all variant spec forms
+               # an AND operation
+               if {[info exists vrnamearr($vrname)] && !$xtspec} {
                   lreplace $vrlist $vrnamearr($vrname) $vrnamearr($vrname)
                } else {
                   incr vridx