VcsCommand: Block auto reload while a command is running

Git rebase is executed in the background, and it can change a file multiple
times in a short period. If we reparse a file while this happens on
Windows, Git fails to replace it, the rebase action fails and the
repository becomes unstable (remains with a modified file).

See discussion at https://github.com/git-for-windows/git/pull/1666

Task-number: QTCREATORBUG-15449
Change-Id: Iba40a770a1df2dfff0dd1c874c491dfbe1cceb58
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/vcsbase/vcscommand.cpp

@@ -27,6 +27,7 @@
 #include "vcsbaseplugin.h"
 #include "vcsoutputwindow.h"
 
+#include <coreplugin/documentmanager.h>
 #include <coreplugin/vcsmanager.h>
 #include <utils/synchronousprocess.h>
 
@@ -56,6 +57,14 @@ VcsCommand::VcsCommand(const QString &workingDirectory,
 
         return proxy;
     });
+    connect(this, &VcsCommand::started, this, [this] {
+        if (flags() & ExpectRepoChanges)
+            Core::DocumentManager::setAutoReloadPostponed(true);
+    });
+    connect(this, &VcsCommand::finished, this, [this] {
+        if (flags() & ExpectRepoChanges)
+            Core::DocumentManager::setAutoReloadPostponed(false);
+    });
 }
 
 const QProcessEnvironment VcsCommand::processEnvironment() const