Sync our ClamAV unrar to the last version that existed in plain C

This is no longer maintained.  We might need to switch to the newer C++
version, that's also closer (identical?) to the official code.

src/unrar.c

@@ -531,9 +531,11 @@ static int read_tables(const unsigned char **fd, unpack_data_t *unpack_data)
 				n = (rar_getbits(unpack_data) >> 9) + 11;
 				rar_addbits(unpack_data, 7);
 			}
+			if (i == 0) {
+				return 0;
+			}
 			while (n-- > 0 && i < table_size) {
-				if (i>0)
-					table[i] = table[i-1];
+				table[i] = table[i - 1];
 				i++;
 			}
 		} else {
@@ -904,9 +906,9 @@ void rar_unpack_init_data(int solid, unpack_data_t *unpack_data)
 		memset(unpack_data->old_dist, 0, sizeof(unpack_data->old_dist));
 		unpack_data->old_dist_ptr= 0;
 		memset(unpack_data->unp_old_table, 0, sizeof(unpack_data->unp_old_table));
+		memset(&unpack_data->LDD, 0, sizeof(unpack_data->LDD));
 		memset(&unpack_data->LD, 0, sizeof(unpack_data->LD));
 		memset(&unpack_data->DD, 0, sizeof(unpack_data->DD));
-		memset(&unpack_data->LDD, 0, sizeof(unpack_data->LDD));
 		memset(&unpack_data->RD, 0, sizeof(unpack_data->RD));
 		memset(&unpack_data->BD, 0, sizeof(unpack_data->BD));
 		unpack_data->last_dist= 0;

src/unrarvm.h

@@ -33,6 +33,10 @@
 #define VM_GLOBALMEMSIZE             0x2000
 #define VM_FIXEDGLOBALSIZE               64
 
+#define VM_FC 1
+#define VM_FZ 2
+#define VM_FS 0x80000000
+
 typedef enum rarvm_commands
 {
   VM_MOV,  VM_CMP,  VM_ADD,  VM_SUB,  VM_JZ,   VM_JNZ,  VM_INC,  VM_DEC,
@@ -49,12 +53,6 @@ typedef enum rarvm_standard_filters {
   VMSF_DELTA, VMSF_UPCASE
 } rarvm_standard_filters_t;
 
-enum VM_Flags {
-	VM_FC=1,
-	VM_FZ=2,
-	VM_FS=0x80000000
-};
-
 enum rarvm_op_type {
 	VM_OPREG,
 	VM_OPINT,