Update 58db06d8 to not even try to use std::fstream with Unicode paths.

Unfortunately there is no portable way to open an Unicode path with
std::fstream. On *nix, it is enough to call the const char*
constructor. On MSVC, it is enough to call a nonstandard
const wchar_t* constructor. However, on MinGW, there is no way at all
to construct an std::fstream with a wide path, not even using
undocumented APIs. (There used to be a const wchar_t* overload added
back in libstdc++ 4.7, but it got removed for a reason that I was not
able to find out.)

src/exportvector.cpp

@@ -702,16 +702,16 @@ void DxfFileWriter::FinishAndCloseFile() {
     interface.writer = this;
     interface.dxf    = &dxf;
 
-    std::fstream stream = ssfstream(filename, std::ios_base::out);
-    if(!stream.good()) {
-        Error("Couldn't write to '%s'", filename.c_str());
-        return;
-    }
-
+    std::stringstream stream;
     dxf.write(stream, &interface, DRW::AC1021, /*bin=*/false);
     paths.clear();
     constraint = NULL;
 
+    if(!WriteFile(filename, stream.str())) {
+        Error("Couldn't write to '%s'", filename.c_str());
+        return;
+    }
+
     if(!interface.messages.empty()) {
         std::string text = "Some aspects of the drawing have no DXF equivalent and "
                            "were not exported:\n";

src/importdxf.cpp

@@ -903,13 +903,14 @@ void ImportDxf(const std::string &filename) {
     DxfReadInterface interface;
     interface.clearBlockTransform();
 
-    std::fstream stream = ssfstream(filename, std::ios_base::in);
-    if(!stream.good()) {
+    std::string data;
+    if(!ReadFile(filename, &data)) {
         Error("Couldn't read from '%s'", filename.c_str());
         return;
     }
 
     SS.UndoRemember();
+    std::stringstream stream(data);
     if(!dxfRW().read(stream, &interface, /*ext=*/false)) {
         Error("Corrupted DXF file.");
     }
@@ -924,13 +925,14 @@ void ImportDwg(const std::string &filename) {
     DxfReadInterface interface;
     interface.clearBlockTransform();
 
-    std::fstream stream = ssfstream(filename, std::ios_base::in);
-    if(!stream.good()) {
+    std::string data;
+    if(!ReadFile(filename, &data)) {
         Error("Couldn't read from '%s'", filename.c_str());
         return;
     }
 
     SS.UndoRemember();
+    std::stringstream stream(data);
     if(!dwgR().read(stream, &interface, /*ext=*/false)) {
         Error("Corrupted DWG file.");
     }

src/platform/unixutil.cpp

@@ -82,13 +82,6 @@ FILE *ssfopen(const std::string &filename, const char *mode)
     return fopen(filename.c_str(), mode);
 }
 
-std::fstream ssfstream(const std::string &filename, std::ios_base::openmode mode)
-{
-    ssassert(filename.length() == strlen(filename.c_str()),
-             "Unexpected null byte in middle of a path");
-    return std::fstream(filename, mode);
-}
-
 void ssremove(const std::string &filename)
 {
     ssassert(filename.length() == strlen(filename.c_str()),

src/platform/w32util.cpp

@@ -136,14 +136,6 @@ FILE *ssfopen(const std::string &filename, const char *mode)
     return _wfopen(Widen(MakeUNCFilename(filename)).c_str(), Widen(mode).c_str());
 }
 
-std::fstream ssfstream(const std::string &filename, std::ios_base::openmode mode)
-{
-    std::string uncFilename = MakeUNCFilename(filename);
-    ssassert(filename.length() == strlen(filename.c_str()),
-             "Unexpected null byte in middle of a path");
-    return std::fstream(Widen(MakeUNCFilename(filename)).c_str(), mode);
-}
-
 void ssremove(const std::string &filename)
 {
     ssassert(filename.length() == strlen(filename.c_str()),

src/solvespace.h

@@ -29,7 +29,7 @@
 #include <map>
 #include <set>
 #include <chrono>
-#include <fstream>
+#include <sstream>
 
 // We declare these in advance instead of simply using FT_Library
 // (defined as typedef FT_LibraryRec_* FT_Library) because including
@@ -367,6 +367,8 @@ void MakeMatrix(double *mat, double a11, double a12, double a13, double a14,
                              double a41, double a42, double a43, double a44);
 std::string MakeAcceleratorLabel(int accel);
 bool FilenameHasExtension(const std::string &str, const char *ext);
+bool ReadFile(const std::string &filename, std::string *data);
+bool WriteFile(const std::string &filename, const std::string &data);
 void Message(const char *str, ...);
 void Error(const char *str, ...);
 void CnfFreezeBool(bool v, const std::string &name);

src/util.cpp

@@ -61,6 +61,33 @@ bool SolveSpace::FilenameHasExtension(const std::string &str, const char *ext)
     return true;
 }
 
+bool SolveSpace::ReadFile(const std::string &filename, std::string *data)
+{
+    FILE *f = ssfopen(filename.c_str(), "rb");
+    if(f == NULL)
+        return false;
+
+    fseek(f, 0, SEEK_END);
+    data->resize(ftell(f));
+    fseek(f, 0, SEEK_SET);
+    fread(&(*data)[0], 1, data->size(), f);
+    fclose(f);
+
+    return true;
+}
+
+bool SolveSpace::WriteFile(const std::string &filename, const std::string &data)
+{
+    FILE *f = ssfopen(filename.c_str(), "wb");
+    if(f == NULL)
+        return false;
+
+    fwrite(&data[0], 1, data.size(), f);
+    fclose(f);
+
+    return true;
+}
+
 int64_t SolveSpace::GetMilliseconds()
 {
     auto timestamp = std::chrono::steady_clock::now().time_since_epoch();

test/harness.cpp

@@ -95,19 +95,6 @@ static std::string Colorize(Color color, std::string input) {
     return input;
 }
 
-static std::string ReadFile(std::string path) {
-    std::string data;
-    FILE *f = ssfopen(path.c_str(), "rb");
-    if(f) {
-        fseek(f, 0, SEEK_END);
-        data.resize(ftell(f));
-        fseek(f, 0, SEEK_SET);
-        fread(&data[0], 1, data.size(), f);
-        fclose(f);
-    }
-    return data;
-}
-
 // Normalizes a savefile. Different platforms have slightly different floating-point
 // behavior, so if we want to compare savefiles byte-by-byte, we need to do something
 // to get rid of irrelevant differences in LSB.
@@ -211,9 +198,10 @@ bool Test::Helper::CheckSave(const char *file, int line, const char *reference)
                      ssprintf("saving file '%s'", refPath.c_str()));
         return false;
     } else {
-        std::string refData = PrepareSavefile(ReadFile(refPath)),
-                    outData = PrepareSavefile(ReadFile(outPath));
-        if(!RecordCheck(refData == outData)) {
+        std::string refData, outData;
+        ReadFile(refPath, &refData);
+        ReadFile(outPath, &outData);
+        if(!RecordCheck(PrepareSavefile(refData) == PrepareSavefile(outData))) {
             PrintFailure(file, line, "savefile doesn't match reference");
             return false;
         }