Merge branch 'jc/maint-name-hash-clear' into maint

* jc/maint-name-hash-clear:
discard_cache: reset lazy name_hash bit

diff --combined read-cache.c
index 35fec468b1951cc17606fca8edc47f809471f652,6c57095f73427ffeaadeaa6018b1f8bdc23ee859..8f96fd17226e26c4b8a1497aace5b9fffb664bbe
--- 1/read-cache.c
--- 2/read-cache.c
+++ b/read-cache.c
@@@ -1155,7 -1155,7 +1155,7 @@@ int read_index_from(struct index_state 
        size_t mmap_size;
  
        errno = EBUSY;
 -      if (istate->alloc)
 +      if (istate->initialized)
                return istate->cache_nr;
  
        errno = ENOENT;
@@@ -1195,7 -1195,6 +1195,7 @@@
         * index size
         */
        istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
 +      istate->initialized = 1;
  
        src_offset = sizeof(*hdr);
        dst_offset = 0;
@@@ -1244,11 -1243,11 +1244,12 @@@ int discard_index(struct index_state *i
        istate->cache_nr = 0;
        istate->cache_changed = 0;
        istate->timestamp = 0;
+       istate->name_hash_initialized = 0;
        free_hash(&istate->name_hash);
        cache_tree_free(&(istate->cache_tree));
        free(istate->alloc);
        istate->alloc = NULL;
 +      istate->initialized = 0;
  
        /* no need to throw away allocated active_cache */
        return 0;