Make volume labels distinguishable from files

So they could be easily filtered out by a parser if needed.

(This is required to make a fatcat extfs helper for Midnight
Commander.)

src/core/FatEntry.cpp

@@ -57,6 +57,11 @@ bool FatEntry::isDirectory()
     return attributes&FAT_ATTRIBUTES_DIR;
 }
 
+bool FatEntry::isVolumeId()
+{
+    return attributes&FAT_ATTRIBUTES_VOLUME_ID;
+}
+
 bool FatEntry::isHidden()
 {
     return attributes&FAT_ATTRIBUTES_HIDE;

src/core/FatEntry.h

@@ -19,6 +19,7 @@ using namespace std;
 // Attributes
 #define FAT_ATTRIBUTES_HIDE     (1<<1)
 #define FAT_ATTRIBUTES_DIR      (1<<4)
+#define FAT_ATTRIBUTES_VOLUME_ID 0x8
 #define FAT_ATTRIBUTES_LONGFILE (0xf)
 #define FAT_ATTRIBUTES_FILE     (0x20)
 
@@ -32,6 +33,7 @@ class FatEntry
 
         string getFilename();
         bool isDirectory();
+        bool isVolumeId();
         bool isHidden();
         bool isErased();
 

src/core/FatSystem.cpp

@@ -459,6 +459,8 @@ void FatSystem::list(vector<FatEntry> &entries)
 
         if (entry.isDirectory()) {
             printf("d");
+        } else if (entry.isVolumeId()) {
+            printf("v");
         } else {
             printf("f");
         }