Fix wrong assumption about transformer output timestamps.

It is true that all outputs of a transformer get the same timestamp
after it has run successfully, but a new output being added afterwards
will have no timestamp at all, so we cannot rely on that as part of the
up-to-date check.

Task-number: QBS-945
Change-Id: I5568ec9854fca46c1ca9fbd5cc95c9b1e3351c05
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

5 files changed, 52 insertions, 7 deletions

diff --git a/src/lib/corelib/buildgraph/executor.cpp b/src/lib/corelib/buildgraph/executor.cpp
index 150133c04..be5a93302 100644
--- a/src/lib/corelib/buildgraph/executor.cpp
+++ b/src/lib/corelib/buildgraph/executor.cpp
@@ -392,13 +392,8 @@ bool Executor::mustExecuteTransformer(const TransformerPtr &transformer) const
             hasAlwaysUpdatedArtifacts = true;
         else if (!m_buildOptions.forceTimestampCheck())
             continue;
-        const bool upToDate = isUpToDate(artifact);
-
-        // The invariant is that all output artifacts of a transformer have the same
-        // "virtual" timestamp. However, if the user requested that on-disk timestamps be evaluated,
-        // they can differ and the oldest output file of the transformer decides.
-        if (!upToDate || !m_buildOptions.forceTimestampCheck())
-            return !upToDate;
+        if (!isUpToDate(artifact))
+            return true;
     }
 
     // If all artifacts in a transformer have "alwaysUpdated" set to false, that transformer
diff --git a/tests/auto/blackbox/testdata/new-output-artifact/input.txt b/tests/auto/blackbox/testdata/new-output-artifact/input.txt
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/blackbox/testdata/new-output-artifact/input.txt
diff --git a/tests/auto/blackbox/testdata/new-output-artifact/new-output-artifact.qbs b/tests/auto/blackbox/testdata/new-output-artifact/new-output-artifact.qbs
new file mode 100644
index 000000000..10e0e4305
--- /dev/null
+++ b/tests/auto/blackbox/testdata/new-output-artifact/new-output-artifact.qbs
@@ -0,0 +1,37 @@
+import qbs
+import qbs.TextFile
+
+Product {
+    name: "theProduct"
+    type: ["output"]
+    property int artifactCount: 99
+    Group {
+        files: ["input.txt"]
+        fileTags: ["input"]
+    }
+    Group {
+        fileTagsFilter: product.type
+        qbs.install: true
+    }
+    Rule {
+        inputs: ["input"]
+        outputFileTags: ["output"]
+        outputArtifacts: {
+            var list = [];
+            for (var i = 0; i < product.artifactCount; ++i)
+                list.push({ filePath: "output_" + i + ".out", fileTags: ["output"]});
+            return list;
+        }
+        prepare: {
+            var cmd = new JavaScriptCommand();
+            cmd.silent = true;
+            cmd.sourceCode = function() {
+                for (var i = 0; i < outputs["output"].length; ++i) {
+                    var f = new TextFile(outputs["output"][i].filePath, TextFile.WriteOnly);
+                    f.close();
+                }
+            }
+            return [cmd];
+        }
+    }
+}
diff --git a/tests/auto/blackbox/tst_blackbox.cpp b/tests/auto/blackbox/tst_blackbox.cpp
index 8fe5f4922..8eed518be 100644
--- a/tests/auto/blackbox/tst_blackbox.cpp
+++ b/tests/auto/blackbox/tst_blackbox.cpp
@@ -2613,6 +2613,18 @@ void TestBlackbox::nestedProperties()
     QVERIFY2(m_qbsStdout.contains("value in higherlevel"), m_qbsStdout.constData());
 }
 
+void TestBlackbox::newOutputArtifact()
+{
+    QDir::setCurrent(testDataDir + "/new-output-artifact");
+    QCOMPARE(runQbs(), 0);
+    QVERIFY(regularFileExists(relativeBuildDir() + "/install-root/output_98.out"));
+    const QString the100thArtifact = relativeBuildDir() + "/install-root/output_99.out";
+    QVERIFY(!regularFileExists(the100thArtifact));
+    QbsRunParameters params(QStringList() << "theProduct.artifactCount:100");
+    QCOMPARE(runQbs(params), 0);
+    QVERIFY(regularFileExists(the100thArtifact));
+}
+
 void TestBlackbox::nonBrokenFilesInBrokenProduct()
 {
     QDir::setCurrent(testDataDir + "/non-broken-files-in-broken-product");
diff --git a/tests/auto/blackbox/tst_blackbox.h b/tests/auto/blackbox/tst_blackbox.h
index e1f9456ca..048c4987b 100644
--- a/tests/auto/blackbox/tst_blackbox.h
+++ b/tests/auto/blackbox/tst_blackbox.h
@@ -162,6 +162,7 @@ private slots:
     void mixedBuildVariants();
     void multipleChanges();
     void nestedProperties();
+    void newOutputArtifact();
     void nodejs();
     void nonBrokenFilesInBrokenProduct();
     void nonDefaultProduct();