Executor: Fix invalid assertion

An artifact whose alwaysUpdated property is false does not need to exist
and is therefore not required to have a valid timestamp.

Change-Id: I642349c49a53e6e45d6b09d1acc87f4c9a0edae9
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

5 files changed, 41 insertions, 1 deletions

diff --git a/changelogs/changes-1.12.1.md b/changelogs/changes-1.12.1.md
index e4edeb136..d9f105941 100644
--- a/changelogs/changes-1.12.1.md
+++ b/changelogs/changes-1.12.1.md
@@ -5,3 +5,4 @@
 * Fixed possible crash when scanning qrc files (QBS-1375).
 * Fixed spurious re-building of .pc and .qbs module files.
 * Fixed possible crash on storing a build graph after re-resolving.
+* Fixed possible assertion on input artifacts with alwaysUpdated == false.
diff --git a/src/lib/corelib/buildgraph/executor.cpp b/src/lib/corelib/buildgraph/executor.cpp
index d2c245c8a..42e3eee8c 100644
--- a/src/lib/corelib/buildgraph/executor.cpp
+++ b/src/lib/corelib/buildgraph/executor.cpp
@@ -397,7 +397,7 @@ bool Executor::isUpToDate(Artifact *artifact) const
     }
 
     for (Artifact *childArtifact : filterByType<Artifact>(artifact->children)) {
-        QBS_CHECK(childArtifact->timestamp().isValid());
+        QBS_CHECK(!childArtifact->alwaysUpdated || childArtifact->timestamp().isValid());
         qCDebug(lcUpToDateCheck) << "child timestamp"
                                  << childArtifact->timestamp().toString()
                                  << childArtifact->filePath();
diff --git a/tests/auto/blackbox/testdata/not-always-updated/not-always-updated.qbs b/tests/auto/blackbox/testdata/not-always-updated/not-always-updated.qbs
new file mode 100644
index 000000000..8d6c1f5da
--- /dev/null
+++ b/tests/auto/blackbox/testdata/not-always-updated/not-always-updated.qbs
@@ -0,0 +1,31 @@
+import qbs.TextFile
+
+Product {
+    type: "p"
+    Rule {
+        multiplex: true
+        Artifact { filePath: "dummy.txt"; fileTags: "t1"; alwaysUpdated: false }
+        prepare: {
+            var cmd = new JavaScriptCommand();
+            cmd.description = "creating dummy";
+            cmd.sourceCode = function() {};
+            return cmd;
+        }
+    }
+    Rule {
+        inputs: "t1"
+        Artifact { filePath: "o.txt"; fileTags: "p" }
+        prepare: {
+            var cmd = new JavaScriptCommand;
+            cmd.description = "creating final";
+            cmd.sourceCode = function() {
+                var f = new TextFile(output.filePath, TextFile.WriteOnly);
+                f.close();
+            };
+            return cmd;
+        }
+    }
+}
+
+
+
diff --git a/tests/auto/blackbox/tst_blackbox.cpp b/tests/auto/blackbox/tst_blackbox.cpp
index 8068aee48..0a846ede7 100644
--- a/tests/auto/blackbox/tst_blackbox.cpp
+++ b/tests/auto/blackbox/tst_blackbox.cpp
@@ -4337,6 +4337,13 @@ void TestBlackbox::nonDefaultProduct()
     QVERIFY2(QFile::exists(nonDefaultAppExe), qPrintable(nonDefaultAppExe));
 }
 
+void TestBlackbox::notAlwaysUpdated()
+{
+    QDir::setCurrent(testDataDir + "/not-always-updated");
+    QCOMPARE(runQbs(), 0);
+    QCOMPARE(runQbs(), 0);
+}
+
 static void switchProfileContents(qbs::Profile &p, qbs::Settings *s, bool on)
 {
     const QString scalarKey = "leaf.scalarProp";
diff --git a/tests/auto/blackbox/tst_blackbox.h b/tests/auto/blackbox/tst_blackbox.h
index 0dcfc5b31..58cc8f6fb 100644
--- a/tests/auto/blackbox/tst_blackbox.h
+++ b/tests/auto/blackbox/tst_blackbox.h
@@ -183,6 +183,7 @@ private slots:
     void nodejs();
     void nonBrokenFilesInBrokenProduct();
     void nonDefaultProduct();
+    void notAlwaysUpdated();
     void nsis();
     void nsisDependencies();
     void outOfDateMarking();