Crashhandler allthreads (#6013)

* [CrashHandler] Suspend all threads on crash

src/crashhandler/main.cpp

@@ -91,8 +91,12 @@ int main( int argc, char *argv[] )
   dlg.show();
   app.exec();
 
-  ResumeThread( stackTrace->thread );
-  CloseHandle( stackTrace->thread );
+
+  for ( HANDLE threadHandle : stackTrace->threads )
+  {
+    ResumeThread( threadHandle );
+    CloseHandle( threadHandle );
+  }
   CloseHandle( stackTrace->process );
 
   return 0;

src/crashhandler/qgsstacktrace.cpp

@@ -29,6 +29,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <tlhelp32.h>
 
 #include <Windows.h>
 #include <DbgHelp.h>
@@ -780,10 +781,35 @@ QgsStackTrace *QgsStackTrace::trace( DWORD processId, DWORD threadId, LPEXCEPTIO
   StackTrace *stackTrace = ( StackTrace * )calloc( sizeof( *stackTrace ), 1 );
   stackTrace->process = OpenProcess( PROCESS_ALL_ACCESS, FALSE, processId );
   stackTrace->thread = OpenThread( THREAD_ALL_ACCESS, FALSE, threadId );
-  SuspendThread( stackTrace->thread );
   trace->process = stackTrace->process;
   trace->thread = stackTrace->thread;
 
+  HANDLE h = CreateToolhelp32Snapshot( TH32CS_SNAPTHREAD, 0 );
+  if ( h != INVALID_HANDLE_VALUE )
+  {
+    THREADENTRY32 te;
+    te.dwSize = sizeof( te );
+    if ( Thread32First( h, &te ) )
+    {
+      do
+      {
+        if ( te.dwSize >= FIELD_OFFSET( THREADENTRY32, th32OwnerProcessID ) +
+             sizeof( te.th32OwnerProcessID ) )
+        {
+          if ( te.th32OwnerProcessID == processId )
+          {
+            HANDLE threadHandle = OpenThread( THREAD_ALL_ACCESS, FALSE, te.th32ThreadID );
+            trace->threads.push_back( threadHandle );
+            SuspendThread( threadHandle );
+          }
+        }
+        te.dwSize = sizeof( te );
+      }
+      while ( Thread32Next( h, &te ) );
+    }
+    CloseHandle( h );
+  }
+
   ReadProcessMemory( stackTrace->process, exception, &remoteException, sizeof( remoteException ), NULL );
   ReadProcessMemory( stackTrace->process, remoteException.ContextRecord, &remoteContextRecord, sizeof( remoteContextRecord ), NULL );
 

src/crashhandler/qgsstacktrace.h

@@ -71,6 +71,7 @@ class QgsStackTrace
 #ifdef _MSC_VER
     HANDLE process;
     HANDLE thread;
+    std::vector<HANDLE> threads;
 
     /**
      * Return a demangled stack backtrace of the caller function.