Don't read index unless necessary

common.c

@@ -140,10 +140,11 @@ lzma_vli find_file_index(void **bdatap) {
     return ret; 
 }  
 
-lzma_vli read_file_index(void) {
+lzma_vli read_file_index(lzma_vli offset) {
-    void *bdata;
+    void *bdata = NULL;
-    lzma_vli offset = find_file_index(&bdata);
+    if (!offset)
-    if (!bdata)
+        offset = find_file_index(&bdata);
+    if (!offset)
         return 0;
     
     while (true) {

list.c

@@ -40,7 +40,7 @@ int main(int argc, char **argv) {
             (uintmax_t)iter.block.uncompressed_size);
     }
     
-    if (tar && read_file_index()) {
+    if (tar && read_file_index(0)) {
         printf("\n");
         dump_file_index(stdout);
         free_file_index();

pixz.h

@@ -57,7 +57,7 @@ bool is_multi_header(const char *name);
 void decode_index(void);
 
 lzma_vli find_file_index(void **bdatap);
-lzma_vli read_file_index(void);
+lzma_vli read_file_index(lzma_vli offset);
 void dump_file_index(FILE *out);
 void free_file_index(void);
 

pread.c

@@ -6,8 +6,8 @@
 #include <getopt.h>
 
 /* TODO
- * - Don't read index unless necessary?
  * - Check sizes of files vs index
+ * - Test against "normal" xz, txz files
  */
 
 #define DEBUG 0
@@ -94,8 +94,9 @@ int main(int argc, char **argv) {
         }
     }
     
-    // TODO: ONly read index if necessary?
+    decode_index();
-    gFileIndexOffset = read_file_index();
+    if (verify)
+        gFileIndexOffset = read_file_index(0);
     wanted_files(argc - optind, argv + optind);
 #if DEBUG
     for (wanted_t *w = gWantedFiles; w; w = w->next)
@@ -122,8 +123,8 @@ int main(int argc, char **argv) {
                 die("Error reading archive entry");
             }
             const char *path = archive_entry_pathname(entry);
-            if (is_multi_header(path))
+//            if (is_multi_header(path))
-                continue;
+//                continue;
             
             size_t size = archive_entry_size(entry);
             if (!w)

read.c

@@ -16,7 +16,7 @@ int main(int argc, char **argv) {
         die("Can't open input file");
     char *target = argv[2];
     
-    if (!read_file_index())
+    if (!read_file_index(0))
         die("File has no index");
     
     extract_file(target);