Do not crash on invalid property assignment in Export item

The crash would happen when creating the export information for a
product whose Export item contained an assignment of the form "x.y:
original", where x is not a module and the assignment was inside a
Properties item.

Task-number: QBS-1362
Change-Id: I900857fcd97852360ec2b75de1b7a791fd948dc4
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/lib/corelib/language/evaluatorscriptclass.cpp b/src/lib/corelib/language/evaluatorscriptclass.cpp
index 18d7fd83f..6db308a7f 100644
--- a/src/lib/corelib/language/evaluatorscriptclass.cpp
+++ b/src/lib/corelib/language/evaluatorscriptclass.cpp
@@ -184,6 +184,18 @@ private:
                     result.second = false;
                     return result;
                 }
+
+                // TODO: Provide a dedicated item type for not-yet-instantiated things that
+                //       look like module instances in the AST visitor.
+                if (item->type() == ItemType::ModuleInstance
+                        && !item->hasProperty(StringConstants::presentProperty())) {
+                    const QString errorMessage = Tr::tr("Trying to assign property '%1' "
+                            "on something that is not a module.").arg(propertyName->toString());
+                    extraScope = engine->currentContext()->throwError(errorMessage);
+                    result.second = false;
+                    return result;
+                }
+
                 while (item->type() == ItemType::ModuleInstance)
                     item = item->prototype();
                 if (item->type() != ItemType::Module && item->type() != ItemType::Export) {