fdo#53006: And detect LO downgrading scenarios...

...that reinstall potentially broken prereg data but do not touch the buildid
file.

Change-Id: I1b02d2c265523dd751d8ef7f2dccb59ed048f568

desktop/source/app/app.cxx

@@ -216,6 +216,18 @@ void removeTree(OUString const & url) {
 // detected here and lead to a removal of user/extensions/bundled, so that
 // Desktop::SynchronizeExtensionRepositories will then definitely resync
 // share/extensions.)
+// As a special case, if you create a UserInstallation with LO >= 3.6.1, then
+// run an old LO <= 3.5.x using share/prereg/bundled on the same
+// UserInstallation (so that it partially overwrites user/extensions/bundled,
+// potentially duplicating component information, but not touching
+// user/extensions/bundled/buildid), and then run the new LO >= 3.6.1 on the
+// same UserInstallation again, it can fail to start (due to the duplicated
+// component information).  Even though such downgrading scenarios at best work
+// by luck in general, the special token LIBO_NON_PREREG_BUNDLED_EXTENSIONS=TRUE
+// is used to detect and fix that problem:  The assumption is that if an old LO
+// <= 3.5.x messed with user/extensions/bundled in the meantime, then it would
+// have rewritten the unorc (dropping the token), and LO >= 3.6.1 can detect
+// that.
 void refreshBundledExtensionsDir() {
     OUString buildId(
         "${$BRAND_BASE_DIR/program/" SAL_CONFIGFILE("version") ":buildid}");
@@ -223,6 +235,12 @@ void refreshBundledExtensionsDir() {
     OUString dir("$BUNDLED_EXTENSIONS_USER");
     rtl::Bootstrap::expandMacros(dir); //TODO: detect failure
     OUString url(dir + "/buildid");
+    OUString nonPrereg(
+        "${$BUNDLED_EXTENSIONS_USER/registry/"
+        "com.sun.star.comp.deployment.component.PackageRegistryBackend/unorc:"
+        "LIBO_NON_PREREG_BUNDLED_EXTENSIONS}");
+    rtl::Bootstrap::expandMacros(nonPrereg);
+    if (nonPrereg == "TRUE") {
         osl::File f(url);
         switch (f.open(osl_File_OpenFlag_Read)) {
         case osl::FileBase::E_None:
@@ -230,7 +248,8 @@ void refreshBundledExtensionsDir() {
                 rtl::ByteSequence s1;
                 osl::FileBase::RC rc = f.readLine(s1);
                 if (f.close() != osl::FileBase::E_None) {
-                SAL_WARN("desktop", "cannot close " + url + " after reading");
+                    SAL_WARN(
+                        "desktop", "cannot close " + url + " after reading");
                 }
                 if (rc != osl::FileBase::E_None) {
                     throw css::uno::RuntimeException(
@@ -240,8 +259,8 @@ void refreshBundledExtensionsDir() {
                 OUString s2(
                     reinterpret_cast< char const * >(s1.getConstArray()),
                     s1.getLength(), RTL_TEXTENCODING_ISO_8859_1);
-                // using ISO 8859-1 avoids any and all conversion errors; the
+                    // using ISO 8859-1 avoids any and all conversion errors;
-                // content should only be a subset of ASCII, anyway
+                    // the content should only be a subset of ASCII, anyway
                 if (s2 == buildId) {
                     return;
                 }
@@ -254,6 +273,7 @@ void refreshBundledExtensionsDir() {
                 "cannot open " + url + " for reading",
                 css::uno::Reference< css::uno::XInterface >());
         }
+    }
     removeTree(dir);
     switch (osl::Directory::createPath(dir)) {
     case osl::FileBase::E_None:
@@ -264,6 +284,7 @@ void refreshBundledExtensionsDir() {
             "cannot create path " + dir,
             css::uno::Reference< css::uno::XInterface >());
     }
+    osl::File f(url);
     if (f.open(osl_File_OpenFlag_Write | osl_File_OpenFlag_Create) !=
         osl::FileBase::E_None)
     {

desktop/source/deployment/registry/component/dp_component.cxx

@@ -1021,6 +1021,13 @@ void BackendImpl::unorc_flush( Reference<XCommandEnvironment> const & xCmdEnv )
         buf.append(LF);
     }
 
+    // See refreshBundledExtensionsDir (desktop/source/app/app.cxx):
+    if (m_eContext == CONTEXT_BUNDLED)
+    {
+        buf.append("LIBO_NON_PREREG_BUNDLED_EXTENSIONS=TRUE");
+        buf.append(LF);
+    }
+
     // write unorc:
     const Reference<io::XInputStream> xData(
         ::xmlscript::createInputStream(