escape kpsewhich arguments on Windows

Makefile.PL

@@ -75,9 +75,11 @@ WriteMakefile(NAME => 'LaTeXML',
     'URI'               => 0,
     'version'           => 0,
     # Windows terminal handling (see Common::Error)
+    # Windows argument escaping (see Util::Pathname)
     ($^O eq 'MSWin32'
       ? ('Win32::Console' => 0,
-        'Win32::Console::ANSI' => 0)
+        'Win32::Console::ANSI' => 0,
+        'Win32::ShellQuote'    => 0)
       : ()),
     # If we have an "old" version of XML::LibXML,
     # we also need XPathContext.

lib/LaTeXML/Util/Pathname.pm

@@ -46,6 +46,13 @@ our @EXPORT = qw( &pathname_find &pathname_findall &pathname_kpsewhich
   &pathname_cwd &pathname_chdir &pathname_mkdir &pathname_copy
   &pathname_installation);
 
+my $ISWINDOWS;
+
+BEGIN {
+  $ISWINDOWS = $^O =~ /^(MSWin|NetWare|cygwin)/i;
+  require Win32::ShellQuote if $ISWINDOWS;
+}
+
 # NOTE: For absolute pathnames, the directory component starts with
 # whatever File::Spec considers to be the volume, or "/".
 #======================================================================
@@ -54,7 +61,6 @@ our @EXPORT = qw( &pathname_find &pathname_findall &pathname_kpsewhich
 ### my $SEP         = '/';                          # [CONSTANT]
 # Some indicators that this is not sufficient? (calls to libraries/externals???)
 # PRELIMINARY test, probably need to be even more careful
-my $ISWINDOWS   = $^O =~ /^(MSWin|NetWare|cygwin)/i;
 my $SEP         = ($ISWINDOWS ? '\\' : '/');    # [CONSTANT]
 my $KPATHSEP    = ($ISWINDOWS ? ';'  : ':');    # [CONSTANT]
 my $LITERAL_RE  = '(?:literal)(?=:)';           # [CONSTANT]
@@ -400,7 +406,12 @@ sub pathname_kpsewhich {
   # For multiple calls, this is slower in general. But MiKTeX, eg., doesn't use texmf ls-R files!
   if ($kpse_toolchain) {
     push(@candidates, $kpse_toolchain); }
-  if ($kpsewhich && open(my $resfh, '-|', $kpsewhich, @candidates)) {
+  if ($kpsewhich && open(my $resfh, '-|',
+      # on Windows, ($kpsewhich, @candidates) is joined into a single string, which most binaries
+      # parse with CommandLineToArgvW, so the arguments must be escaped accordingly
+      # WARNING: @candidates MUST NOT be empty to guarantee that Perl runs $kpsewhich directly rather
+      # than through a shell/cmd.exe
+      $ISWINDOWS ? Win32::ShellQuote::quote_system_list($kpsewhich, @candidates) : ($kpsewhich, @candidates))) {
     my $result = <$resfh>;     # we only need the first line
     { local $/; <$resfh>; }    # discard the rest of the output
     close($resfh);             # ignore exit status (only one of @candidates exists, usually)