Transcode Windows paths to current code page

This is an alternative approach to using the std::wstring versions of exiv2 methods that are not available in v0.28.x (see Exiv2/exiv2#2637). It should also allow non ascii paths to be used when libexiv2 has been compiled without wstring methods enabled. The proper approach is to set the Windows code page to utf-8, but this probably won't work on old Windows, and it's not clear how to do it for a Python application. Instead we transcode paths from utf-8 to the current code page, which could fail.
jim-easterbrook · Dec 21, 2023 · 1d499ed · 1d499ed
1 parent c1d4aa6
commit 1d499ed
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Showing 11 changed files with 244 additions and 10 deletions.
diff --git a/src/interface/basicio.i b/src/interface/basicio.i
@@ -25,6 +25,7 @@
 %include "shared/enum.i"
 %include "shared/keep_reference.i"
 %include "shared/unique_ptr.i"
+%include "shared/windows_path.i"
 
 %include "std_string.i"
 
@@ -65,6 +66,12 @@ UNIQUE_PTR(Exiv2::BasicIo);
 %noexception Exiv2::RemoteIo::tell;
 %noexception Exiv2::MemIo::write;
 
+// Convert path encoding on Windows
+WINDOWS_PATH(const std::wstring& wpath)
+WINDOWS_PATH(const std::wstring& wOrgPathpath)
+WINDOWS_PATH(const std::wstring& wOrgPath)
+WINDOWS_PATH(const std::wstring& wurl)
+
 // BasicIo return values keep a reference to the Image they refer to
 KEEP_REFERENCE(Exiv2::BasicIo&)
 

diff --git a/src/interface/exif.i b/src/interface/exif.i
@@ -22,14 +22,10 @@
 %include "shared/containers.i"
 %include "shared/data_iterator.i"
 %include "shared/keep_reference.i"
+%include "shared/windows_path.i"
 
 %include "stdint.i"
 %include "std_string.i"
-#ifndef SWIGIMPORTED
-#ifdef EXV_UNICODE_PATH
-%include "std_wstring.i"
-#endif
-#endif
 
 %import "metadatum.i"
 %import "tags.i"
@@ -53,6 +49,9 @@ DATA_ITERATOR_CLASSES(
 
 DATA_CONTAINER(Exiv2::ExifData, Exiv2::Exifdatum, Exiv2::ExifKey)
 
+// Convert path encoding on Windows
+WINDOWS_PATH(const std::wstring& wpath)
+
 // Ignore const overloads of some methods
 %ignore Exiv2::ExifData::operator[];
 %ignore Exiv2::ExifData::begin() const;

diff --git a/src/interface/image.i b/src/interface/image.i
@@ -24,13 +24,9 @@
 %include "shared/buffers.i"
 %include "shared/enum.i"
 %include "shared/keep_reference.i"
+%include "shared/windows_path.i"
 
 %include "std_string.i"
-#ifndef SWIGIMPORTED
-#ifdef EXV_UNICODE_PATH
-%include "std_wstring.i"
-#endif
-#endif
 
 %import "basicio.i";
 %import "exif.i";
@@ -57,6 +53,9 @@ INPUT_BUFFER_RO_EX(const Exiv2::byte* data, size_t size)
     }
 %}
 
+// Convert path encoding on Windows
+WINDOWS_PATH(const std::string& path)
+
 // Simplify handling of default parameters
 %typemap(default) bool useCurl {$1 = true;}
 %ignore Exiv2::ImageFactory::createIo(std::string const &);

diff --git a/src/interface/preview.i b/src/interface/preview.i
@@ -23,6 +23,7 @@
 %include "shared/preamble.i"
 %include "shared/buffers.i"
 %include "shared/keep_reference.i"
+%include "shared/windows_path.i"
 
 %include "std_string.i"
 %include "std_vector.i"
@@ -41,6 +42,9 @@
 %noexception Exiv2::PreviewImage::wextension;
 %noexception Exiv2::PreviewImage::width;
 
+// Convert path encoding on Windows
+WINDOWS_PATH(const std::wstring& wpath)
+
 // Convert getPreviewProperties result to a Python tuple
 %template() std::vector<Exiv2::PreviewProperties>;
 

diff --git a/src/interface/shared/windows_path.i b/src/interface/shared/windows_path.i
@@ -0,0 +1,54 @@
+// python-exiv2 - Python interface to libexiv2
+// http://github.com/jim-easterbrook/python-exiv2
+// Copyright (C) 2023  Jim Easterbrook  [email protected]
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+// If exiv2's wstring methods are available then use them!
+#ifdef EXV_UNICODE_PATH
+%include "std_wstring.i"
+#endif
+
+// Function to convert utf-8 string to current code page
+%fragment("transcode_path", "header") {
+static void transcode_path(std::string *path) {
+%#ifdef _WIN32
+    UINT acp = GetACP();
+    if (acp == CP_UTF8)
+        return;
+    // Convert utf-8 path to active code page, via widechar version
+    int wide_len = MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1, NULL, 0);
+    std::wstring wide_str;
+    wide_str.resize(wide_len);
+    if (MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1,
+                            &wide_str[0], (int)wide_str.size()) >= 0) {
+        int new_len = WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                                          NULL, 0, NULL, NULL);
+        path->resize(new_len);
+        WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                            &(*path)[0], (int)path->size(), NULL, NULL);
+    }
+%#endif
+};
+}
+
+// Macro to convert Windows paths from utf-8 to current code page
+%define WINDOWS_PATH(signature)
+#ifndef EXV_UNICODE_PATH
+%typemap(check, fragment="transcode_path") signature {
+    transcode_path($1);
+}
+#endif
+%enddef // WINDOWS_PATH
diff --git a/src/swig-0_27_0/image_wrap.cxx b/src/swig-0_27_0/image_wrap.cxx
@@ -4455,6 +4455,27 @@ SWIG_AsVal_unsigned_SS_short (PyObject * obj, unsigned short *val)
   return res;
 }
 
+
+static void transcode_path(std::string *path) {
+#ifdef _WIN32
+    UINT acp = GetACP();
+    if (acp == CP_UTF8)
+        return;
+    // Convert utf-8 path to active code page, via widechar version
+    int wide_len = MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1, NULL, 0);
+    std::wstring wide_str;
+    wide_str.resize(wide_len);
+    if (MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1,
+                            &wide_str[0], (int)wide_str.size()) >= 0) {
+        int new_len = WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                                          NULL, 0, NULL, NULL);
+        path->resize(new_len);
+        WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                            &(*path)[0], (int)path->size(), NULL, NULL);
+    }
+#endif
+};
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -5966,6 +5987,9 @@ SWIGINTERN PyObject *_wrap_ImageFactory_createIo(PyObject *self, PyObject *args)
     } 
     arg2 = static_cast< bool >(val2);
   }
+  {
+    transcode_path(arg1);
+  }
   {
     try {
       result = Exiv2::ImageFactory::createIo((std::string const &)*arg1,arg2);
@@ -6021,6 +6045,9 @@ SWIGINTERN PyObject *_wrap_ImageFactory_open__SWIG_0(PyObject *self, Py_ssize_t
     } 
     arg2 = static_cast< bool >(val2);
   }
+  {
+    transcode_path(arg1);
+  }
   {
     try {
       {
@@ -6171,6 +6198,9 @@ SWIGINTERN PyObject *_wrap_ImageFactory_create__SWIG_0(PyObject *self, Py_ssize_
     }
     arg2 = ptr;
   }
+  {
+    transcode_path(arg2);
+  }
   {
     try {
       {
@@ -6285,6 +6315,9 @@ SWIGINTERN PyObject *_wrap_ImageFactory_getType__SWIG_0(PyObject *self, Py_ssize
     }
     arg1 = ptr;
   }
+  {
+    transcode_path(arg1);
+  }
   {
     try {
       result = (int)Exiv2::ImageFactory::getType((std::string const &)*arg1);

diff --git a/src/swig-0_27_0/preview_wrap.cxx b/src/swig-0_27_0/preview_wrap.cxx
@@ -5434,6 +5434,27 @@ SWIG_AsPtr_std_string (PyObject * obj, std::string **val)
 }
 
 
+static void transcode_path(std::string *path) {
+#ifdef _WIN32
+    UINT acp = GetACP();
+    if (acp == CP_UTF8)
+        return;
+    // Convert utf-8 path to active code page, via widechar version
+    int wide_len = MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1, NULL, 0);
+    std::wstring wide_str;
+    wide_str.resize(wide_len);
+    if (MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1,
+                            &wide_str[0], (int)wide_str.size()) >= 0) {
+        int new_len = WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                                          NULL, 0, NULL, NULL);
+        path->resize(new_len);
+        WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                            &(*path)[0], (int)path->size(), NULL, NULL);
+    }
+#endif
+};
+
+
   #define SWIG_From_long   PyInt_FromLong 
 
 SWIGINTERN size_t Exiv2_PreviewImage___len__(Exiv2::PreviewImage *self){
@@ -5986,6 +6007,9 @@ SWIGINTERN PyObject *_wrap_PreviewImage_writeFile(PyObject *self, PyObject *args
     }
     arg2 = ptr;
   }
+  {
+    transcode_path(arg2);
+  }
   {
     try {
       result = (long)((Exiv2::PreviewImage const *)arg1)->writeFile((std::string const &)*arg2);

diff --git a/src/swig-0_27_4/image_wrap.cxx b/src/swig-0_27_4/image_wrap.cxx
@@ -4455,6 +4455,27 @@ SWIG_AsVal_unsigned_SS_short (PyObject * obj, unsigned short *val)
   return res;
 }
 
+
+static void transcode_path(std::string *path) {
+#ifdef _WIN32
+    UINT acp = GetACP();
+    if (acp == CP_UTF8)
+        return;
+    // Convert utf-8 path to active code page, via widechar version
+    int wide_len = MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1, NULL, 0);
+    std::wstring wide_str;
+    wide_str.resize(wide_len);
+    if (MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1,
+                            &wide_str[0], (int)wide_str.size()) >= 0) {
+        int new_len = WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                                          NULL, 0, NULL, NULL);
+        path->resize(new_len);
+        WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                            &(*path)[0], (int)path->size(), NULL, NULL);
+    }
+#endif
+};
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -5966,6 +5987,9 @@ SWIGINTERN PyObject *_wrap_ImageFactory_createIo(PyObject *self, PyObject *args)
     } 
     arg2 = static_cast< bool >(val2);
   }
+  {
+    transcode_path(arg1);
+  }
   {
     try {
       result = Exiv2::ImageFactory::createIo((std::string const &)*arg1,arg2);
@@ -6021,6 +6045,9 @@ SWIGINTERN PyObject *_wrap_ImageFactory_open__SWIG_0(PyObject *self, Py_ssize_t
     } 
     arg2 = static_cast< bool >(val2);
   }
+  {
+    transcode_path(arg1);
+  }
   {
     try {
       {
@@ -6171,6 +6198,9 @@ SWIGINTERN PyObject *_wrap_ImageFactory_create__SWIG_0(PyObject *self, Py_ssize_
     }
     arg2 = ptr;
   }
+  {
+    transcode_path(arg2);
+  }
   {
     try {
       {
@@ -6285,6 +6315,9 @@ SWIGINTERN PyObject *_wrap_ImageFactory_getType__SWIG_0(PyObject *self, Py_ssize
     }
     arg1 = ptr;
   }
+  {
+    transcode_path(arg1);
+  }
   {
     try {
       result = (int)Exiv2::ImageFactory::getType((std::string const &)*arg1);

diff --git a/src/swig-0_27_4/preview_wrap.cxx b/src/swig-0_27_4/preview_wrap.cxx
@@ -5434,6 +5434,27 @@ SWIG_AsPtr_std_string (PyObject * obj, std::string **val)
 }
 
 
+static void transcode_path(std::string *path) {
+#ifdef _WIN32
+    UINT acp = GetACP();
+    if (acp == CP_UTF8)
+        return;
+    // Convert utf-8 path to active code page, via widechar version
+    int wide_len = MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1, NULL, 0);
+    std::wstring wide_str;
+    wide_str.resize(wide_len);
+    if (MultiByteToWideChar(CP_UTF8, 0, &(*path)[0], -1,
+                            &wide_str[0], (int)wide_str.size()) >= 0) {
+        int new_len = WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                                          NULL, 0, NULL, NULL);
+        path->resize(new_len);
+        WideCharToMultiByte(acp, 0, &wide_str[0], -1,
+                            &(*path)[0], (int)path->size(), NULL, NULL);
+    }
+#endif
+};
+
+
   #define SWIG_From_long   PyInt_FromLong 
 
 SWIGINTERN size_t Exiv2_PreviewImage___len__(Exiv2::PreviewImage *self){
@@ -5986,6 +6007,9 @@ SWIGINTERN PyObject *_wrap_PreviewImage_writeFile(PyObject *self, PyObject *args
     }
     arg2 = ptr;
   }
+  {
+    transcode_path(arg2);
+  }
   {
     try {
       result = (long)((Exiv2::PreviewImage const *)arg1)->writeFile((std::string const &)*arg2);