Change tracking: Be more sensitive to environment changes.

Contrary to what the old code assumed, it is not enough to compare the
values of environment variables that were used while resolving the
project: A command run by a transformer might be sensitive to
environment changes as well (e.g. gcc to CPLUS_INCLUDE_PATH).
Note: This does not mean we will rebuild everything when anything in the
environment changes; it means that *if* a file is rebuilt, its command
will see the new environment instead of the old one.

Change-Id: I7916b8c40f1440564034ec3317c549ebd4e988a0
Reviewed-by: Jake Petroules <jake.petroules@theqtcompany.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

3 files changed, 9 insertions, 0 deletions

diff --git a/tests/auto/blackbox/testdata/trackExternalProductChanges/hidden/hiddenheaderqbs.h b/tests/auto/blackbox/testdata/trackExternalProductChanges/hidden/hiddenheaderqbs.h
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/blackbox/testdata/trackExternalProductChanges/hidden/hiddenheaderqbs.h
diff --git a/tests/auto/blackbox/testdata/trackExternalProductChanges/including.cpp b/tests/auto/blackbox/testdata/trackExternalProductChanges/including.cpp
new file mode 100644
index 000000000..bfe738d1d
--- /dev/null
+++ b/tests/auto/blackbox/testdata/trackExternalProductChanges/including.cpp
@@ -0,0 +1,3 @@
+#include <hiddenheaderqbs.h>
+
+void f() {}
diff --git a/tests/auto/blackbox/testdata/trackExternalProductChanges/project.qbs b/tests/auto/blackbox/testdata/trackExternalProductChanges/project.qbs
index df1ddc1f9..451b0a25a 100644
--- a/tests/auto/blackbox/testdata/trackExternalProductChanges/project.qbs
+++ b/tests/auto/blackbox/testdata/trackExternalProductChanges/project.qbs
@@ -6,4 +6,10 @@ CppApplication {
     property stringList filesFromEnv: qbs.getEnv("QBS_TEST_PULL_IN_FILE_VIA_ENV")
                                       ? ["environmentChange.cpp"] : []
     files: ["main.cpp"].concat(FileList.fileList()).concat(filesFromEnv).concat(FileList.filesFromFs(qbs))
+
+    Group {
+        condition: qbs.getEnv("INCLUDE_PATH_TEST")
+        name: "file that needs help from the environment to find a header"
+        files: "including.cpp"
+    }
 }