Fwd: New Defects reported by Coverity Scan for git

I looked at this report for a while. My current understanding:
* its detection was triggered by including rs/move-array,
  f331ab9d4c (use MOVE_ARRAY, 2017-07-15)
* But it is harmless, because the scan logic does not understand
  how ALLOC_GROW works. It assumes that
  done_pbase_paths_alloc can be larger
  than done_pbase_paths_num + 1, while done_pbase_paths
  is NULL, such that the memory allocation is not triggered.
  If that were the case, then we have 2 subsequent dereferences
  of a NULL pointer right after that. But by inspecting the use
  of _alloc and _num the initial assumption does not seem possible.

Stefan

---------- Forwarded message ----------
From:  <scan-admin@coverity.com>
Date: Tue, Jul 18, 2017 at 2:53 AM
Subject: New Defects reported by Coverity Scan for git
To: sbeller@google.com

Hi,

Please find the latest report on new defect(s) introduced to git found with Coverity Scan.

2 new defect(s) introduced to git found with Coverity Scan. 1 defect(s), reported by Coverity Scan earlier, were marked fixed in the recent build analyzed by Coverity Scan.

New defect(s) Reported-by: Coverity Scan Showing 2 of 2 defect(s)

** CID 1415508: Null pointer dereferences (FORWARD_NULL) /builtin/pack-objects.c: 1292 in check_pbase_path()

________________________________________________________________________________________________________ *** CID 1415508: Null pointer dereferences (FORWARD_NULL) /builtin/pack-objects.c: 1292 in check_pbase_path() 1286 } 1287 return -lo-1; 1288 } 1289 1290 static int check_pbase_path(unsigned hash) 1291 {

1292 int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash); 1293 if (0 <= pos) 1294 return 1; 1295 pos = -pos - 1; 1296 ALLOC_GROW(done_pbase_paths, 1297 done_pbase_paths_num + 1,

** CID 1415507: Null pointer dereferences (FORWARD_NULL) /builtin/pack-objects.c: 1303 in check_pbase_path()

________________________________________________________________________________________________________ *** CID 1415507: Null pointer dereferences (FORWARD_NULL) /builtin/pack-objects.c: 1303 in check_pbase_path() 1297 done_pbase_paths_num + 1, 1298 done_pbase_paths_alloc); 1299 done_pbase_paths_num++; 1300 if (pos < done_pbase_paths_num) 1301 MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos, 1302 done_pbase_paths_num - pos - 1);

1303 done_pbase_paths[pos] = hash; 1304 return 0; 1305 } 1306 1307 static void add_preferred_base_object(const char *name) 1308 {

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