Fixes Tix build by correcting the directories used by Tcl and Tk. (#3391)

PCbuild/tcl.vcxproj

@@ -53,7 +53,7 @@
   <PropertyGroup>
     <TclOpts>msvcrt</TclOpts>
     <TclOpts Condition="$(Configuration) == 'Debug'">symbols,msvcrt</TclOpts>
-    <TclDirs>INSTALLDIR="$(OutDir.TrimEnd(`\`))" INSTALL_DIR="$(OutDir.TrimEnd(`\`))"</TclDirs>
+    <TclDirs>BUILDDIRTOP="$(BuildDirTop)" INSTALLDIR="$(OutDir.TrimEnd(`\`))" INSTALL_DIR="$(OutDir.TrimEnd(`\`))"</TclDirs>
     <DebugFlags Condition="'$(Configuration)' == 'Debug'">DEBUGFLAGS="-wd4456 -wd4457 -wd4458 -wd4459 -wd4996"</DebugFlags>
     <WarningsFlags>WARNINGS="-W3 -wd4311 -wd4312"</WarningsFlags>
     <NMakeBuildCommandLine>setlocal

PCbuild/tcltk.props

@@ -36,6 +36,7 @@
     <BuildDirTop>Release</BuildDirTop>
     <BuildDirTop Condition="$(Configuration) == 'Debug'">Debug</BuildDirTop>
     <BuildDirTop Condition="$(TclMachine) != 'IX86'">$(BuildDirTop)_$(TclMachine)</BuildDirTop>
+    <BuildDirTop Condition="$(PlatformToolset) == 'v141'">$(BuildDirTop)_VC13</BuildDirTop>
     <BuildDirTop Condition="$(PlatformToolset) == 'v140'">$(BuildDirTop)_VC13</BuildDirTop>
     <BuildDirTop Condition="$(PlatformToolset) == 'v120'">$(BuildDirTop)_VC12</BuildDirTop>
     <BuildDirTop Condition="$(PlatformToolset) == 'v110'">$(BuildDirTop)_VC11</BuildDirTop>

PCbuild/tk.vcxproj

@@ -54,7 +54,7 @@
   <PropertyGroup>
     <TkOpts>msvcrt</TkOpts>
     <TkOpts Condition="$(Configuration) == 'Debug'">symbols,msvcrt</TkOpts>
-    <TkDirs>TCLDIR="$(tclDir.TrimEnd(`\`))" INSTALLDIR="$(OutDir.TrimEnd(`\`))"</TkDirs>
+    <TkDirs>BUILDDIRTOP="$(BuildDirTop)" TCLDIR="$(tclDir.TrimEnd(`\`))" INSTALLDIR="$(OutDir.TrimEnd(`\`))"</TkDirs>
     <DebugFlags Condition="'$(Configuration)' == 'Debug'">DEBUGFLAGS="-wd4456 -wd4457 -wd4458 -wd4459 -wd4996"</DebugFlags>
     <WarningsFlags>WARNINGS="-W3 -wd4244 -wd4267 -wd4311 -wd4312 -wd4334"</WarningsFlags>
     <NMakeBuildCommandLine>setlocal