Fixed "Slic3r crashes when sending STLs with special characters to the printer"

https://github.com/prusa3d/Slic3r/issues/597
The "Send to OctoPrint" function will now send the file name encoded
in UTF-8, so the file name will not get mangled.

The C++ Slic3r::encode_path() function was returning a string to Perl,
which was marked as UTF-8. This has been fixed, now encode_path() returns
a plain Perl string.

Added path_to_filename, path_to_stem, path_to_extension, path_to_parent_path
Perl wrappers to boost::filesystem::path splitting functionality
to be able to split UTF-8 encoded files on Windows correctly.

lib/Slic3r/GUI/Plater.pm

@@ -1460,15 +1460,19 @@ sub send_gcode {
     my $ua = LWP::UserAgent->new;
     $ua->timeout(180);
     
-    my $enc_path = Slic3r::encode_path($self->{send_gcode_file});
     my $res = $ua->post(
         "http://" . $self->{config}->octoprint_host . "/api/files/local",
         Content_Type => 'form-data',
         'X-Api-Key' => $self->{config}->octoprint_apikey,
         Content => [
-            # OctoPrint doesn't like Windows paths so we use basename()
-            # Also, since we need to read from filesystem we process it through encode_path()
-            file => [ $enc_path, basename($enc_path) ],
+            file => [ 
+                # On Windows, the path has to be encoded in local code page for perl to be able to open it.
+                Slic3r::encode_path($self->{send_gcode_file}),
+                # Remove the UTF-8 flag from the perl string, so the LWP::UserAgent can insert 
+                # the UTF-8 encoded string into the request as a byte stream.
+                Encode::encode_utf8(Slic3r::path_to_filename($self->{send_gcode_file}))
+            ],
+            print => $self->{send_gcode_file_print} ? 1 : 0,
         ],
     );
     

xs/src/libslic3r/Utils.hpp

@@ -25,16 +25,39 @@ void set_data_dir(const std::string &path);
 // Return a full path to the GUI resource files.
 const std::string& data_dir();
 
-extern std::string encode_path(const char *src);
+// A special type for strings encoded in the local Windows 8-bit code page.
+// This type is only needed for Perl bindings to relay to Perl that the string is raw, not UTF-8 encoded.
+typedef std::string local_encoded_string;
+
+// Convert an UTF-8 encoded string into local coding.
+// On Windows, the UTF-8 string is converted to a local 8-bit code page.
+// On OSX and Linux, this function does no conversion and returns a copy of the source string.
+extern local_encoded_string encode_path(const char *src);
 extern std::string decode_path(const char *src);
 extern std::string normalize_utf8_nfc(const char *src);
 
+// File path / name / extension splitting utilities, working with UTF-8,
+// to be published to Perl.
+namespace PerlUtils {
+    // Get a file name including the extension.
+    extern std::string path_to_filename(const char *src);
+    // Get a file name without the extension.
+    extern std::string path_to_stem(const char *src);
+    // Get just the extension.
+    extern std::string path_to_extension(const char *src);
+    // Get a directory without the trailing slash.
+    extern std::string path_to_parent_path(const char *src);
+};
+
 // Timestamp formatted for header_slic3r_generated().
 extern std::string timestamp_str();
 // Standard "generated by Slic3r version xxx timestamp xxx" header string, 
 // to be placed at the top of Slic3r generated files.
 inline std::string header_slic3r_generated() { return std::string("generated by " SLIC3R_FORK_NAME " " SLIC3R_VERSION " " ) + timestamp_str(); }
 
+// Encode a file into a multi-part HTTP response with a given boundary.
+std::string octoprint_encode_file_send_request_content(const char *path, bool select, bool print, const char *boundary);
+
 // Compute the next highest power of 2 of 32-bit v
 // http://graphics.stanford.edu/~seander/bithacks.html
 template<typename T>

xs/src/libslic3r/utils.cpp

@@ -10,6 +10,8 @@
 #include <boost/algorithm/string/predicate.hpp>
 #include <boost/date_time/local_time/local_time.hpp>
 #include <boost/filesystem.hpp>
+#include <boost/filesystem/path.hpp>
+#include <boost/nowide/fstream.hpp>
 #include <boost/nowide/integration/filesystem.hpp>
 #include <boost/nowide/convert.hpp>
 
@@ -235,6 +237,17 @@ std::string normalize_utf8_nfc(const char *src)
     return boost::locale::normalize(src, boost::locale::norm_nfc, locale_utf8);
 }
 
+namespace PerlUtils {
+    // Get a file name including the extension.
+    std::string path_to_filename(const char *src)       { return boost::filesystem::path(src).filename().string(); }
+    // Get a file name without the extension.
+    std::string path_to_stem(const char *src)           { return boost::filesystem::path(src).stem().string(); }
+    // Get just the extension.
+    std::string path_to_extension(const char *src)      { return boost::filesystem::path(src).extension().string(); }
+    // Get a directory without the trailing slash.
+    std::string path_to_parent_path(const char *src)    { return boost::filesystem::path(src).parent_path().string(); }
+};
+
 std::string timestamp_str()
 {
     const auto now = boost::posix_time::second_clock::local_time();
@@ -247,4 +260,31 @@ std::string timestamp_str()
     return buf;
 }
 
+std::string octoprint_encode_file_send_request_content(const char *cpath, bool select, bool print, const char *boundary)
+{
+    // Read the complete G-code string into a string buffer.
+    // It will throw if the file cannot be open or read.
+    std::stringstream str_stream;
+    {
+        boost::nowide::ifstream ifs(cpath);
+        str_stream << ifs.rdbuf();
+    }
+
+    boost::filesystem::path path(cpath);
+    std::string request = boundary + '\n';
+    request += "Content-Disposition: form-data; name=\"";
+    request += path.stem().string() + "\"; filename=\"" + path.filename().string() + "\"\n";
+    request += "Content-Type: application/octet-stream\n\n";
+    request += str_stream.str();
+    request += boundary + '\n';
+    request += "Content-Disposition: form-data; name=\"select\"\n\n";
+    request += select ? "true\n" : "false\n";
+    request += boundary + '\n';
+    request += "Content-Disposition: form-data; name=\"print\"\n\n";
+    request += print ? "true\n" : "false\n";
+    request += boundary + '\n';
+
+    return request;
+}
+
 }; // namespace Slic3r

xs/xsp/XS.xsp

@@ -91,7 +91,7 @@ data_dir()
         RETVAL = const_cast<char*>(Slic3r::data_dir().c_str());
     OUTPUT: RETVAL
 
-std::string
+local_encoded_string
 encode_path(src)
     const char *src;
     CODE:
@@ -112,6 +112,34 @@ normalize_utf8_nfc(src)
         RETVAL = Slic3r::normalize_utf8_nfc(src);
     OUTPUT: RETVAL
 
+std::string
+path_to_filename(src)
+    const char *src;
+    CODE:
+        RETVAL = Slic3r::PerlUtils::path_to_filename(src);
+    OUTPUT: RETVAL
+
+std::string
+path_to_stem(src)
+    const char *src;
+    CODE:
+        RETVAL = Slic3r::PerlUtils::path_to_stem(src);
+    OUTPUT: RETVAL
+
+std::string
+path_to_extension(src)
+    const char *src;
+    CODE:
+        RETVAL = Slic3r::PerlUtils::path_to_extension(src);
+    OUTPUT: RETVAL
+
+std::string
+path_to_parent_path(src)
+    const char *src;
+    CODE:
+        RETVAL = Slic3r::PerlUtils::path_to_parent_path(src);
+    OUTPUT: RETVAL
+
 void
 xspp_test_croak_hangs_on_strawberry()
     CODE:

xs/xsp/my.map

@@ -1,6 +1,7 @@
 coordf_t T_NV
 
 std::string                     T_STD_STRING
+local_encoded_string     		T_STD_STRING_LOCAL_ENCODING
 t_config_option_key             T_STD_STRING
 t_model_material_id             T_STD_STRING
 
@@ -279,6 +280,14 @@ T_STD_STRING
       $var = std::string(c, len);
     }
 
+INPUT
+T_STD_STRING_LOCAL_ENCODING
+    {
+      size_t len;
+      const char * c = SvPV($arg, len);
+      $var = std::string(c, len);
+    }
+
 T_STD_VECTOR_STD_STRING
 	if (SvROK($arg) && SvTYPE(SvRV($arg))==SVt_PVAV) {
 	  AV* av = (AV*)SvRV($arg);
@@ -438,6 +447,9 @@ OUTPUT
 T_STD_STRING
     $arg = newSVpvn_utf8( $var.c_str(), $var.length(), true );
 
+T_STD_STRING_LOCAL_ENCODING
+    $arg = newSVpvn( $var.c_str(), $var.length() );
+
 T_STD_VECTOR_STD_STRING
 	AV* av = newAV();
 	$arg = newRV_noinc((SV*)av);