fix(windows console): properly bind windows console

Signed-off-by: Rachel Powers <508861+Ryex@users.noreply.github.com>

launcher/Application.cpp

@@ -135,13 +135,16 @@
 #include "updater/MacSparkleUpdater.h"
 #endif
 
-
 #if defined Q_OS_WIN32
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #endif
-#include <windows.h>
+#include <fcntl.h>
+#include <io.h>
 #include <stdio.h>
+#include <windows.h>
+#include <iostream>
+
 #endif
 
 #define STRINGIFY(x) #x
@@ -168,33 +171,116 @@ void appDebugOutput(QtMsgType type, const QMessageLogContext &context, const QSt
     fflush(stderr);
 }
 
+}  // namespace
+
+
+#if defined Q_OS_WIN32
+
+// taken from https://stackoverflow.com/a/25927081
+// getting a proper output to console with redirection support on windows is apearently hell
+void BindCrtHandlesToStdHandles(bool bindStdIn, bool bindStdOut, bool bindStdErr)
+{
+    // Re-initialize the C runtime "FILE" handles with clean handles bound to "nul". We do this because it has been
+    // observed that the file number of our standard handle file objects can be assigned internally to a value of -2
+    // when not bound to a valid target, which represents some kind of unknown internal invalid state. In this state our
+    // call to "_dup2" fails, as it specifically tests to ensure that the target file number isn't equal to this value
+    // before allowing the operation to continue. We can resolve this issue by first "re-opening" the target files to
+    // use the "nul" device, which will place them into a valid state, after which we can redirect them to our target
+    // using the "_dup2" function.
+    if (bindStdIn) {
+        FILE* dummyFile;
+        freopen_s(&dummyFile, "nul", "r", stdin);
     }
+    if (bindStdOut) {
+        FILE* dummyFile;
+        freopen_s(&dummyFile, "nul", "w", stdout);
+    }
+    if (bindStdErr) {
+        FILE* dummyFile;
+        freopen_s(&dummyFile, "nul", "w", stderr);
+    }
+
+    // Redirect unbuffered stdin from the current standard input handle
+    if (bindStdIn) {
+        HANDLE stdHandle = GetStdHandle(STD_INPUT_HANDLE);
+        if (stdHandle != INVALID_HANDLE_VALUE) {
+            int fileDescriptor = _open_osfhandle((intptr_t)stdHandle, _O_TEXT);
+            if (fileDescriptor != -1) {
+                FILE* file = _fdopen(fileDescriptor, "r");
+                if (file != NULL) {
+                    int dup2Result = _dup2(_fileno(file), _fileno(stdin));
+                    if (dup2Result == 0) {
+                        setvbuf(stdin, NULL, _IONBF, 0);
+                    }
+                }
+            }
+        }
+    }
+
+    // Redirect unbuffered stdout to the current standard output handle
+    if (bindStdOut) {
+        HANDLE stdHandle = GetStdHandle(STD_OUTPUT_HANDLE);
+        if (stdHandle != INVALID_HANDLE_VALUE) {
+            int fileDescriptor = _open_osfhandle((intptr_t)stdHandle, _O_TEXT);
+            if (fileDescriptor != -1) {
+                FILE* file = _fdopen(fileDescriptor, "w");
+                if (file != NULL) {
+                    int dup2Result = _dup2(_fileno(file), _fileno(stdout));
+                    if (dup2Result == 0) {
+                        setvbuf(stdout, NULL, _IONBF, 0);
+                    }
+                }
+            }
+        }
+    }
+
+    // Redirect unbuffered stderr to the current standard error handle
+    if (bindStdErr) {
+        HANDLE stdHandle = GetStdHandle(STD_ERROR_HANDLE);
+        if (stdHandle != INVALID_HANDLE_VALUE) {
+            int fileDescriptor = _open_osfhandle((intptr_t)stdHandle, _O_TEXT);
+            if (fileDescriptor != -1) {
+                FILE* file = _fdopen(fileDescriptor, "w");
+                if (file != NULL) {
+                    int dup2Result = _dup2(_fileno(file), _fileno(stderr));
+                    if (dup2Result == 0) {
+                        setvbuf(stderr, NULL, _IONBF, 0);
+                    }
+                }
+            }
+        }
+    }
+
+    // Clear the error state for each of the C++ standard stream objects. We need to do this, as attempts to access the
+    // standard streams before they refer to a valid target will cause the iostream objects to enter an error state. In
+    // versions of Visual Studio after 2005, this seems to always occur during startup regardless of whether anything
+    // has been read from or written to the targets or not.
+    if (bindStdIn) {
+        std::wcin.clear();
+        std::cin.clear();
+    }
+    if (bindStdOut) {
+        std::wcout.clear();
+        std::cout.clear();
+    }
+    if (bindStdErr) {
+        std::wcerr.clear();
+        std::cerr.clear();
+    }
+}
+#endif
 
 Application::Application(int& argc, char** argv) : QApplication(argc, argv)
 {
 #if defined Q_OS_WIN32
-    // attach the parent console
+    // attach the parent console if stdout not already captured
-    if(AttachConsole(ATTACH_PARENT_PROCESS))
+    auto stdout_type = GetFileType(GetStdHandle(STD_OUTPUT_HANDLE));
-    {
+    if (stdout_type == FILE_TYPE_CHAR || stdout_type == FILE_TYPE_UNKNOWN) {
-        // if attach succeeds, reopen and sync all the i/o
+        if (AttachConsole(ATTACH_PARENT_PROCESS)) {
-        if(freopen("CON", "w", stdout))
+            BindCrtHandlesToStdHandles(true, true, true);
-        {
-            std::cout.sync_with_stdio();
-        }
-        if(freopen("CON", "w", stderr))
-        {
-            std::cerr.sync_with_stdio();
-        }
-        if(freopen("CON", "r", stdin))
-        {
-            std::cin.sync_with_stdio();
-        }
-        auto out = GetStdHandle (STD_OUTPUT_HANDLE);
-        DWORD written;
-        const char * endline = "\n";
-        WriteConsole(out, endline, strlen(endline), &written, NULL);
             consoleAttached = true;
         }
+    }
 #endif
     setOrganizationName(BuildConfig.LAUNCHER_NAME);
     setOrganizationDomain(BuildConfig.LAUNCHER_DOMAIN);