From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 11 Oct 2016 21:21:35 +0000 (-0700)
Subject: Merge branch 'jk/verify-packfile-gently' into maint
X-Git-Tag: v2.10.2~28
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/6823506f364cd02589dd4485108516bd6bea8d9e?ds=inline;hp=-c

Merge branch 'jk/verify-packfile-gently' into maint

A low-level function verify_packfile() was meant to show errors
that were detected without dying itself, but under some conditions
it didn't and died instead, which has been fixed.

* jk/verify-packfile-gently:
verify_packfile: check pack validity before accessing data
---

6823506f364cd02589dd4485108516bd6bea8d9e
diff --combined pack-check.c
index d123846ea2,5af987c09b..c5c7763323
--- a/pack-check.c
+++ b/pack-check.c
@@@ -57,11 -57,8 +57,8 @@@ static int verify_packfile(struct packe
  	int err = 0;
  	struct idx_entry *entries;
  
- 	/* Note that the pack header checks are actually performed by
- 	 * use_pack when it first opens the pack file.  If anything
- 	 * goes wrong during those checks then the call will die out
- 	 * immediately.
- 	 */
+ 	if (!is_pack_valid(p))
+ 		return error("packfile %s cannot be accessed", p->pack_name);
  
  	git_SHA1_Init(&ctx);
  	do {
@@@ -105,8 -102,6 +102,8 @@@
  		void *data;
  		enum object_type type;
  		unsigned long size;
 +		off_t curpos;
 +		int data_valid;
  
  		if (p->index_version > 1) {
  			off_t offset = entries[i].offset;
@@@ -118,25 -113,8 +115,25 @@@
  					    sha1_to_hex(entries[i].sha1),
  					    p->pack_name, (uintmax_t)offset);
  		}
 -		data = unpack_entry(p, entries[i].offset, &type, &size);
 -		if (!data)
 +
 +		curpos = entries[i].offset;
 +		type = unpack_object_header(p, w_curs, &curpos, &size);
 +		unuse_pack(w_curs);
 +
 +		if (type == OBJ_BLOB && big_file_threshold <= size) {
 +			/*
 +			 * Let check_sha1_signature() check it with
 +			 * the streaming interface; no point slurping
 +			 * the data in-core only to discard.
 +			 */
 +			data = NULL;
 +			data_valid = 0;
 +		} else {
 +			data = unpack_entry(p, entries[i].offset, &type, &size);
 +			data_valid = 1;
 +		}
 +
 +		if (data_valid && !data)
  			err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
  				    sha1_to_hex(entries[i].sha1), p->pack_name,
  				    (uintmax_t)entries[i].offset);