From 68cc555740b3f3f8f82a59cca34b1af247cc3909 Mon Sep 17 00:00:00 2001
From: maddes-b <maddes-b@users.noreply.github.com>
Date: Mon, 7 Sep 2020 20:13:55 +0200
Subject: [PATCH] Enhanced platform support of hook script check-mime-type.pl
MIME-Version: 1.0
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* contrib/hook-scripts/check-mime-type.pl:
  (svnlook) Cross Platform: sane executable determination

Patch by: Matthias Bücher <maddes+subversion@maddes.net>

[1] http://perldoc.perl.org/perlport.html#PLATFORMS
---
 contrib/hook-scripts/check-mime-type.pl | 129 ++++++++++++++++++++----
 1 file changed, 109 insertions(+), 20 deletions(-)

diff --git a/contrib/hook-scripts/check-mime-type.pl b/contrib/hook-scripts/check-mime-type.pl
index 79c37d26eb..716b1a0792 100755
--- a/contrib/hook-scripts/check-mime-type.pl
+++ b/contrib/hook-scripts/check-mime-type.pl
@@ -28,6 +28,15 @@
 
 use strict;
 use Carp;
+use Config;
+use Cwd;
+use Env;
+use File::Which  qw(which);
+use File::Temp  qw(tempdir tempfile);
+
+my $old_dir;
+my $os_windows = $^O eq 'MSWin32';
+my $os_dos = $^O eq 'dos';
 
 # Turn on warnings the best way depending on the Perl version.
 BEGIN {
@@ -35,6 +44,12 @@ BEGIN {
     { require warnings; import warnings; }
   else
     { $^W = 1; }
+
+  $old_dir = getcwd;
+}
+
+END {
+  chdir($old_dir);
 }
 
 
@@ -42,31 +57,58 @@ BEGIN {
 # Configuration section.
 
 # Svnlook path.
-my $svnlook = "/usr/bin/svnlook";
+my $svnlook;
 
 # Since the path to svnlook depends upon the local installation
 # preferences, check that the required program exists to insure that
 # the administrator has set up the script properly.
 {
-  my $ok = 1;
-  foreach my $program ($svnlook)
+  my $svnlook_exe = 'svnlook' . $Config{_exe};
+  my @svnlook_paths;
+
+  if ($os_windows || $os_dos)
+    {
+      # On Windows/DOS the environment is available
+      my $svn_bindir = $ENV{'SVN_BINDIR'};
+      if (defined $svn_bindir and length $svn_bindir)
+        {
+          $svnlook_paths[++$#svnlook_paths] = "$svn_bindir/$svnlook_exe";
+        }
+
+      $svnlook = which($svnlook_exe);
+      if (defined $svnlook and length $svnlook)
+        {
+          $svnlook_paths[++$#svnlook_paths] = $svnlook;
+        }
+      undef $svnlook;
+    }
+
+  # On Unix the environment is empty, define fallback with absolute path
+  $svnlook_paths[++$#svnlook_paths] = "/usr/bin/$svnlook_exe";
+
+  foreach my $program (@svnlook_paths)
     {
       if (-e $program)
         {
           unless (-x $program)
             {
-              warn "$0: required program `$program' is not executable, ",
-                   "edit $0.\n";
-              $ok = 0;
+              warn "$0: program `$program' is not executable.\n";
+              next;
             }
+          $svnlook = $program;
+          last;
         }
       else
         {
-          warn "$0: required program `$program' does not exist, edit $0.\n";
-          $ok = 0;
+          warn "$0: program `$program' does not exist.\n";
+          next;
         }
     }
-  exit 1 unless $ok;
+  unless (defined $svnlook and length $svnlook)
+    {
+      warn "$0: required program `$svnlook_exe' does not exist or is not executable, maybe have to edit $0.\n";
+      exit 1;
+    }
 }
 
 ######################################################################
@@ -95,9 +137,9 @@ sub ACCESS_READ_WRITE () { 'read-write' }
 ######################################################################
 # Harvest data using svnlook.
 
-# Change into /tmp so that svnlook diff can create its .svnlook
+# Change into temp dir so that svnlook diff can create its .svnlook
 # directory.
-my $tmp_dir = '/tmp';
+my $tmp_dir = tempdir( TMPDIR => 1, CLEANUP => 1 );
 chdir($tmp_dir)
   or die "$0: cannot chdir `$tmp_dir': $!\n";
 
@@ -220,19 +262,66 @@ sub safe_read_from_pipe
     {
       croak "$0: safe_read_from_pipe passed no arguments.\n";
     }
-  print "Running @_\n";
-  my $pid = open(SAFE_READ, '-|', @_);
-  unless (defined $pid)
+
+  my $openfork_available = !($os_windows || $os_dos);
+  if ($openfork_available)
     {
-      die "$0: cannot fork: $!\n";
+      print "Running @_\n";
+      my $pid = open(SAFE_READ, '-|', @_);
+      unless (defined $pid)
+        {
+          die "$0: cannot fork: $!\n";
+        }
+      unless ($pid)
+        {
+          open(STDERR, ">&STDOUT")
+            or die "$0: cannot dup STDOUT: $!\n";
+          exec(@_)
+            or die "$0: cannot exec `@_': $!\n";
+        }
     }
-  unless ($pid)
+  else
     {
-      open(STDERR, ">&STDOUT")
-        or die "$0: cannot dup STDOUT: $!\n";
-      exec(@_)
-        or die "$0: cannot exec `@_': $!\n";
+      # Redirect the comment into a temp file and use that to work around
+      # Windows' (non-)handling of multi-line commands.
+      my @commandline = ();
+      my $command;
+      my $comment;
+
+      while ($command = shift)
+        {
+          if ("-m" eq $command)
+            {
+              $comment = shift;
+              my ($handle, $tmpfile) = tempfile( DIR => $tmp_dir);
+              print $handle $comment;
+              close($handle);
+
+              push(@commandline, "--file");
+              push(@commandline, $tmpfile);
+            }
+          else
+            {
+              # Munge the command to protect it from the command line
+              $command =~ s/\"/\\\"/g;
+              if ($command =~ m"\s") { $command = "\"$command\""; }
+              if ($command eq "") { $command = "\"\""; }
+              if ($command =~ m"\n")
+                {
+                  warn "$0: carriage return detected in command - may not work\n";
+                }
+              push(@commandline, $command);
+            }
+        }
+
+      print "Running @commandline\n";
+      if ( $comment ) { print $comment; }
+
+      # Now do the pipe.
+      open(SAFE_READ, "@commandline |")
+        or die "$0: cannot pipe to command: $!\n";
     }
+
   my @output;
   while (<SAFE_READ>)
     {
-- 
2.24.3 (Apple Git-128)