[libcalamares] Add name-for-partition-type method

- add apidox to all the untranslatedFS() methods
- add the most-basic of untranslatedFS(), which works on a given
  FileSystem::Type; this one can handle special cases where
  Cala needs a different untranslated name than what KPMCore provides.

src/libcalamares/partition/FileSystem.cpp

@@ -74,5 +74,17 @@ prettyNameForFileSystemType( FileSystem::Type t )
     }
 }
 
+QString
+untranslatedFS( FileSystem::Type t )
+{
+    switch ( t )
+    {
+    case FileSystem::Type::ReiserFS:
+        return QStringLiteral( "reiserfs" );
+    default:
+        return FileSystem::nameForType( t, { QStringLiteral( "C" ) } );
+    }
+}
+
 }  // namespace Partition
 }  // namespace CalamaresUtils

src/libcalamares/partition/FileSystem.h

@@ -38,12 +38,30 @@ namespace Partition
 {
 QString DLLEXPORT prettyNameForFileSystemType( FileSystem::Type t );
 
+/** @brief Returns a machine-readable identifier for the filesystem type
+ *
+ * This identifier is  used in filesystem manipulation --
+ * e.g. when mounting the filesystem, or in /etc/fstab. It
+ * is almost always just what KPMCore says it is, with
+ * the following exceptions:
+ *  - reiserfs is called "reiser" by KPMCore, "reiserfs" by Calamares
+ */
+QString DLLEXPORT untranslatedFS( FileSystem::Type t );
+
+/** @brief Returns the machine-readable identifier for the given @p fs
+ *
+ * See notes for untranslatedFS(), above.
+ */
 static inline QString
 untranslatedFS( FileSystem& fs )
 {
-    return fs.name( { QStringLiteral( "C" ) } );
+    return untranslatedFS( fs.type() );
 }
 
+/** @brief Returns a machine-readable identifier for the given @p fs
+ *
+ * Returns an empty string is the @p fs is not valid (e.g. nullptr).
+ */
 static inline QString
 untranslatedFS( FileSystem* fs )
 {

src/libcalamares/partition/KPMTests.cpp

@@ -20,6 +20,8 @@
 
 #include "utils/Logger.h"
 
+#include "FileSystem.h"
+
 #include <kpmcore/core/partitiontable.h>
 #include <kpmcore/fs/filesystem.h>
 
@@ -100,6 +102,30 @@ KPMTests::testFSNames()
     QVERIFY( fsNames.contains( "ext2" ) );
     QVERIFY( fsNames.contains( "ext4" ) );
     QVERIFY( fsNames.contains( "reiser" ) );
+
+    QStringList calaFSNames;
+    calaFSNames.reserve( fstypes.count() );
+    for ( const auto t : fstypes )
+    {
+        QString s = CalamaresUtils::Partition::untranslatedFS( t );
+        calaFSNames.append( s );
+    }
+
+    QVERIFY( calaFSNames.contains( "ext2" ) );
+    QVERIFY( calaFSNames.contains( "ext4" ) );
+    QVERIFY( !calaFSNames.contains( "reiser" ) );
+    QVERIFY( calaFSNames.contains( "reiserfs" ) );  // whole point of Cala's own implementation
+
+    // Lists are the same except for .. the exceptions
+    QStringList exceptionalNames { "reiser", "reiserfs" };
+    for ( const auto& s : fsNames )
+    {
+        QVERIFY( exceptionalNames.contains( s ) || calaFSNames.contains( s ) );
+    }
+    for ( const auto& s : calaFSNames )
+    {
+        QVERIFY( exceptionalNames.contains( s ) || fsNames.contains( s ) );
+    }
 }