Lower the default response file threshold a bit on Windowsv1.9.1

It has been observed that values somewhat below 32000 can cause issues
as well, so use a "safety offset".

Task-number: QBS-1201
Change-Id: Ic82a4b4a9d770d8d92b955d1e70194de5baeae1b
Reviewed-by: Jake Petroules <jake.petroules@qt.io>

2 files changed, 11 insertions, 1 deletions

diff --git a/src/lib/corelib/buildgraph/rulecommands.cpp b/src/lib/corelib/buildgraph/rulecommands.cpp
index 6419d4e58..0044bdd5c 100644
--- a/src/lib/corelib/buildgraph/rulecommands.cpp
+++ b/src/lib/corelib/buildgraph/rulecommands.cpp
@@ -202,11 +202,19 @@ void ProcessCommand::setupForJavaScript(QScriptValue targetObject)
 
 ProcessCommand::ProcessCommand()
     : m_maxExitCode(0)
-    , m_responseFileThreshold(HostOsInfo::isWindowsHost() ? 32000 : -1)
+    , m_responseFileThreshold(defaultResponseFileThreshold())
     , m_responseFileArgumentIndex(0)
 {
 }
 
+int ProcessCommand::defaultResponseFileThreshold() const
+{
+    // TODO: Non-Windows platforms likely have their own limits. Investigate.
+    return HostOsInfo::isWindowsHost()
+            ? 31000 // 32000 minus "safety offset"
+            : -1;
+}
+
 void ProcessCommand::getEnvironmentFromList(const QStringList &envList)
 {
     m_environment.clear();
diff --git a/src/lib/corelib/buildgraph/rulecommands.h b/src/lib/corelib/buildgraph/rulecommands.h
index 4e0d88056..57d73a623 100644
--- a/src/lib/corelib/buildgraph/rulecommands.h
+++ b/src/lib/corelib/buildgraph/rulecommands.h
@@ -129,6 +129,8 @@ public:
 private:
     ProcessCommand();
 
+    int defaultResponseFileThreshold() const;
+
     void load(PersistentPool &pool);
     void store(PersistentPool &pool) const;