Introduce a fundamental.override.ini for bootstrap variables

...that is looked for next to the application and, when present, overrides all
the other ways of setting bootstrap variables.  LibreOffice itself does not
bring along such a fundamental.override.ini, but it can be convenient for an
administrator to place one in the installation (which can then not be modified
or overridden by end users).

(For convenience, the naming of this ini-file starts to deviate from the old and
rather pointless tradition of naming our ini-files *rc vs. *.ini on different
platforms.)

Change-Id: I057cc67b1af1d806587c3a4dc0bc31c28e79d22b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/162187
Tested-by: Stephan Bergmann <stephan.bergmann@allotropia.de>
Reviewed-by: Stephan Bergmann <stephan.bergmann@allotropia.de>

2 files changed, 95 insertions, 46 deletions

diff --git a/include/rtl/bootstrap.h b/include/rtl/bootstrap.h
index 620a3a577944..93ece37ba95c 100644
--- a/include/rtl/bootstrap.h
+++ b/include/rtl/bootstrap.h
@@ -41,27 +41,29 @@ extern "C" {
    the next level is tried. Every query starts at the first level again, so
    that one setting may be taken from the 3rd and one from the 1st level.
 
-   1st level: explicitly set variables via rtl_bootstrap_set()
+   1st level: a fundamental.override.ini next to the application
 
-   2nd level: command line arguments. A `-env:SETTINGNAME=value` is given on
+   2nd level: explicitly set variables via rtl_bootstrap_set()
+
+   3rd level: command line arguments. A `-env:SETTINGNAME=value` is given on
    command line. This allows giving an application a certain setting, even
    if an ini-file exists (especially useful for e.g. daemons that want to
    start an executable with dynamical changing settings).
 
-   3rd level: environment variables. The application tries to get the
+   4th level: environment variables. The application tries to get the
    setting from the environment.
 
-   4th level: executable ini-file. Every application looks for an ini-file.
+   5th level: executable ini-file. Every application looks for an ini-file.
    The filename defaults to `/absolute/path/to/executable[rc|.ini]`
    without .bin or .exe suffix. The ini-filename can be
    set by the special command line parameter
    `-env:INIFILENAME=/absolute/path/to/inifile` at runtime or it may
    be set at compile time by an API-call.
 
-   5th level: URE_BOOTSTRAP ini-file. If the bootstrap variable URE_BOOTSTRAP
+   6th level: URE_BOOTSTRAP ini-file. If the bootstrap variable URE_BOOTSTRAP
    expands to the URL of an ini-file, that ini-file is searched.
 
-   6th level: default. An application can have some default settings decided
+   7th level: default. An application can have some default settings decided
    at compile time, which allow the application to run even with no
    deployment settings.
 
diff --git a/sal/rtl/bootstrap.cxx b/sal/rtl/bootstrap.cxx
index 7f5d4317636a..3ac3e4137d26 100644
--- a/sal/rtl/bootstrap.cxx
+++ b/sal/rtl/bootstrap.cxx
@@ -209,34 +209,38 @@ static void getExecutableDirectory_Impl(rtl_uString ** ppDirURL)
     rtl_uString_newFromStr_WithLength(ppDirURL,fileName.getStr(),nDirEnd);
 }
 
-static OUString & getIniFileName_Impl()
-{
-    static OUString aStaticName = []() {
-        OUString fileName;
+static OUString getIniFileName(bool overriding) {
+    OUString fileName;
 
 #if defined IOS
-        // On iOS hardcode the inifile as "rc" in the .app
-        // directory. Apps are self-contained anyway, there is no
-        // possibility to have several "applications" in the same
-        // installation location with different inifiles.
-        const char *inifile = [[@"vnd.sun.star.pathname:" stringByAppendingString: [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent: @"rc"]] UTF8String];
-        fileName = OUString(inifile, strlen(inifile), RTL_TEXTENCODING_UTF8);
-        resolvePathnameUrl(&fileName);
+    // On iOS hardcode the inifile as "rc" in the .app
+    // directory. Apps are self-contained anyway, there is no
+    // possibility to have several "applications" in the same
+    // installation location with different inifiles.
+    const char *inifile = [[@"vnd.sun.star.pathname:" stringByAppendingString: [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent: (overriding ? @"fundamental.override.ini" : @"rc")]] UTF8String];
+    fileName = OUString(inifile, strlen(inifile), RTL_TEXTENCODING_UTF8);
+    resolvePathnameUrl(&fileName);
 #elif defined ANDROID
-        // Apps are self-contained on Android, too, can as well hardcode
-        // it as "rc" in the "/assets" directory, i.e.  inside the app's
-        // .apk (zip) archive as the /assets/rc file.
-        fileName = OUString("vnd.sun.star.pathname:/assets/rc");
-        resolvePathnameUrl(&fileName);
+    // Apps are self-contained on Android, too, can as well hardcode
+    // it as "rc" in the "/assets" directory, i.e.  inside the app's
+    // .apk (zip) archive as the /assets/rc file.
+    fileName = overriding
+        ? OUString("vnd.sun.star.pathname:/assets/fundamental.override.ini")
+        : OUString("vnd.sun.star.pathname:/assets/rc");
+    resolvePathnameUrl(&fileName);
 #else
-        if (getFromCommandLineArgs("INIFILENAME", &fileName))
-        {
-            resolvePathnameUrl(&fileName);
-        }
-        else
-        {
-            osl_getExecutableFile(&(fileName.pData));
+    if (!overriding && getFromCommandLineArgs("INIFILENAME", &fileName))
+    {
+        resolvePathnameUrl(&fileName);
+    }
+    else
+    {
+        osl_getExecutableFile(&(fileName.pData));
 
+        if (overriding) {
+            auto const i = fileName.lastIndexOf('/') + 1;
+            fileName = fileName.replaceAt(i, fileName.getLength() - i, u"fundamental.override.ini");
+        } else {
             // get rid of a potential executable extension
             OUString progExt = ".bin";
             if (fileName.getLength() > progExt.getLength()
@@ -254,19 +258,31 @@ static OUString & getIniFileName_Impl()
 
             // append config file suffix
             fileName += SAL_CONFIGFILE("");
+        }
 
 #ifdef MACOSX
-            // We keep only executables in the MacOS folder, and all
-            // rc files in LIBO_ETC_FOLDER (typically "Resources").
-            sal_Int32 off = fileName.lastIndexOf( "/MacOS/" );
-            if (off != -1)
-                fileName = fileName.replaceAt(off + 1, strlen("MacOS"), LIBO_ETC_FOLDER);
+        // We keep only executables in the MacOS folder, and all
+        // rc files in LIBO_ETC_FOLDER (typically "Resources").
+        sal_Int32 off = fileName.lastIndexOf( "/MacOS/" );
+        if (off != -1)
+            fileName = fileName.replaceAt(off + 1, strlen("MacOS"), LIBO_ETC_FOLDER);
 #endif
-        }
+    }
 #endif
 
-        return fileName;
-    }();
+    return fileName;
+}
+
+static OUString const & getOverrideIniFileName_Impl()
+{
+    static OUString aStaticName = getIniFileName(true);
+
+    return aStaticName;
+}
+
+static OUString & getIniFileName_Impl()
+{
+    static OUString aStaticName = getIniFileName(false);
 
     return aStaticName;
 }
@@ -284,6 +300,7 @@ static void EnsureNoFinalSlash (OUString & url)
 struct Bootstrap_Impl
 {
     sal_Int32 _nRefCount;
+    Bootstrap_Impl * _override_base_ini;
     Bootstrap_Impl * _base_ini;
 
     NameValueVector _nameValueVector;
@@ -315,23 +332,47 @@ struct Bootstrap_Impl
 
 Bootstrap_Impl::Bootstrap_Impl( OUString const & rIniName )
     : _nRefCount( 0 ),
+      _override_base_ini( nullptr ),
       _base_ini( nullptr ),
       _iniName (rIniName)
 {
-    OUString base_ini(getIniFileName_Impl());
+    OUString override_base_ini(getOverrideIniFileName_Impl());
     // normalize path
-    FileStatus status( osl_FileStatus_Mask_FileURL );
-    DirectoryItem dirItem;
-    if (DirectoryItem::get(base_ini, dirItem) == DirectoryItem::E_None &&
-        dirItem.getFileStatus(status) == DirectoryItem::E_None)
+    FileStatus override_status( osl_FileStatus_Mask_FileURL );
+    DirectoryItem override_dirItem;
+    bool skip_base_ini = false;
+    if (DirectoryItem::get(override_base_ini, override_dirItem) == DirectoryItem::E_None &&
+        override_dirItem.getFileStatus(override_status) == DirectoryItem::E_None)
     {
-        base_ini = status.getFileURL();
-        if (rIniName != base_ini)
+        override_base_ini = override_status.getFileURL();
+        if (rIniName != override_base_ini)
+        {
+            _override_base_ini = static_cast< Bootstrap_Impl * >(
+                rtl_bootstrap_args_open(override_base_ini.pData));
+        }
+        else
+        {
+            skip_base_ini = true;
+        }
+    }
+
+    if (!skip_base_ini) {
+        OUString base_ini(getIniFileName_Impl());
+        // normalize path
+        FileStatus status( osl_FileStatus_Mask_FileURL );
+        DirectoryItem dirItem;
+        if (DirectoryItem::get(base_ini, dirItem) == DirectoryItem::E_None &&
+            dirItem.getFileStatus(status) == DirectoryItem::E_None)
         {
-            _base_ini = static_cast< Bootstrap_Impl * >(
-                rtl_bootstrap_args_open(base_ini.pData));
+            base_ini = status.getFileURL();
+            if (rIniName != base_ini)
+            {
+                _base_ini = static_cast< Bootstrap_Impl * >(
+                    rtl_bootstrap_args_open(base_ini.pData));
+            }
         }
     }
+
     SAL_INFO("sal.bootstrap", "Bootstrap_Impl(): sFile=" << _iniName);
     oslFileHandle handle;
     if (!_iniName.isEmpty() &&
@@ -366,6 +407,8 @@ Bootstrap_Impl::~Bootstrap_Impl()
 {
     if (_base_ini)
         rtl_bootstrap_args_close( _base_ini );
+    if (_override_base_ini)
+        rtl_bootstrap_args_close( _override_base_ini );
 }
 
 namespace {
@@ -423,6 +466,10 @@ bool Bootstrap_Impl::getValue(
     if (override && getDirectValue(key, value, mode, requestStack))
         return true;
 
+    if (_override_base_ini != nullptr
+        && _override_base_ini->getDirectValue(key, value, mode, requestStack))
+        return true;
+
     if (key == "_OS")
     {
         rtl_uString_assign(