To: vim_dev@googlegroups.com
Subject: Patch 8.1.0798
Fcc: outbox
From: Bram Moolenaar <Bram@moolenaar.net>
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------------

Patch 8.1.0798
Problem:    Changing a blob while iterating over it works strangely.
Solution:   Make a copy of the Blob before iterating.
Files:	    src/blob.c, src/proto/blob.pro, src/eval.c,
            src/testdir/test_blob.vim


*** ../vim-8.1.0797/src/blob.c	2019-01-17 16:32:49.465289104 +0100
--- src/blob.c	2019-01-23 21:47:19.587282840 +0100
***************
*** 57,62 ****
--- 57,84 ----
  	++b->bv_refcount;
  }
  
+     int
+ blob_copy(typval_T *from, typval_T *to)
+ {
+     int	    ret = OK;
+ 
+     to->v_type = VAR_BLOB;
+     if (from->vval.v_blob == NULL)
+ 	to->vval.v_blob = NULL;
+     else if (rettv_blob_alloc(to) == FAIL)
+ 	ret = FAIL;
+     else
+     {
+ 	int  len = from->vval.v_blob->bv_ga.ga_len;
+ 
+ 	if (len > 0)
+ 	    to->vval.v_blob->bv_ga.ga_data =
+ 			    vim_memsave(from->vval.v_blob->bv_ga.ga_data, len);
+ 	to->vval.v_blob->bv_ga.ga_len = len;
+     }
+     return ret;
+ }
+ 
      void
  blob_free(blob_T *b)
  {
*** ../vim-8.1.0797/src/proto/blob.pro	2019-01-13 17:48:00.994125660 +0100
--- src/proto/blob.pro	2019-01-23 21:26:04.464036293 +0100
***************
*** 2,7 ****
--- 2,8 ----
  blob_T *blob_alloc(void);
  int rettv_blob_alloc(typval_T *rettv);
  void rettv_blob_set(typval_T *rettv, blob_T *b);
+ int blob_copy(typval_T *from, typval_T *to);
  void blob_free(blob_T *b);
  void blob_unref(blob_T *b);
  long blob_len(blob_T *b);
*** ../vim-8.1.0797/src/eval.c	2019-01-19 17:43:03.405449224 +0100
--- src/eval.c	2019-01-23 21:41:36.389748231 +0100
***************
*** 2587,2593 ****
      char_u	*expr;
      typval_T	tv;
      list_T	*l;
-     blob_T	*b;
  
      *errp = TRUE;	/* default: there is an error */
  
--- 2587,2592 ----
***************
*** 2632,2647 ****
  	    }
  	    else if (tv.v_type == VAR_BLOB)
  	    {
! 		b = tv.vval.v_blob;
! 		if (b == NULL)
! 		    clear_tv(&tv);
! 		else
  		{
! 		    // No need to increment the refcount, it's already set for
! 		    // the blob being used in "tv".
! 		    fi->fi_blob = b;
! 		    fi->fi_bi = 0;
  		}
  	    }
  	    else
  	    {
--- 2631,2647 ----
  	    }
  	    else if (tv.v_type == VAR_BLOB)
  	    {
! 		fi->fi_bi = 0;
! 		if (tv.vval.v_blob != NULL)
  		{
! 		    typval_T btv;
! 
! 		    // Make a copy, so that the iteration still works when the
! 		    // blob is changed.
! 		    blob_copy(&tv, &btv);
! 		    fi->fi_blob = btv.vval.v_blob;
  		}
+ 		clear_tv(&tv);
  	    }
  	    else
  	    {
***************
*** 8076,8082 ****
  /*
   * Copy the values from typval_T "from" to typval_T "to".
   * When needed allocates string or increases reference count.
!  * Does not make a copy of a list or dict but copies the reference!
   * It is OK for "from" and "to" to point to the same item.  This is used to
   * make a copy later.
   */
--- 8076,8082 ----
  /*
   * Copy the values from typval_T "from" to typval_T "to".
   * When needed allocates string or increases reference count.
!  * Does not make a copy of a list, blob or dict but copies the reference!
   * It is OK for "from" and "to" to point to the same item.  This is used to
   * make a copy later.
   */
***************
*** 8216,8234 ****
  		ret = FAIL;
  	    break;
  	case VAR_BLOB:
! 	    to->v_type = VAR_BLOB;
! 	    if (from->vval.v_blob == NULL)
! 		to->vval.v_blob = NULL;
! 	    else if (rettv_blob_alloc(to) == FAIL)
! 		ret = FAIL;
! 	    else
! 	    {
! 		int  len = from->vval.v_blob->bv_ga.ga_len;
! 
! 		to->vval.v_blob->bv_ga.ga_data =
! 			    vim_memsave(from->vval.v_blob->bv_ga.ga_data, len);
! 		to->vval.v_blob->bv_ga.ga_len = len;
! 	    }
  	    break;
  	case VAR_DICT:
  	    to->v_type = VAR_DICT;
--- 8216,8222 ----
  		ret = FAIL;
  	    break;
  	case VAR_BLOB:
! 	    ret = blob_copy(from, to);
  	    break;
  	case VAR_DICT:
  	    to->v_type = VAR_DICT;
*** ../vim-8.1.0797/src/testdir/test_blob.vim	2019-01-22 22:20:13.374961397 +0100
--- src/testdir/test_blob.vim	2019-01-23 21:35:46.092132992 +0100
***************
*** 154,159 ****
--- 154,160 ----
      call assert_equal(i, byte)
      let i += 1
    endfor
+     call assert_equal(4, i)
  
    let blob = 0z00
    call remove(blob, 0)
***************
*** 161,166 ****
--- 162,180 ----
    for byte in blob
      call assert_error('loop over empty blob')
    endfor
+ 
+   let blob = 0z0001020304
+   let i = 0
+   for byte in blob
+     call assert_equal(i, byte)
+     if i == 1
+       call remove(blob, 0)
+     elseif i == 3
+       call remove(blob, 3)
+     endif
+     let i += 1
+   endfor
+   call assert_equal(5, i)
  endfunc
  
  func Test_blob_concatenate()
*** ../vim-8.1.0797/src/version.c	2019-01-23 21:14:59.165314597 +0100
--- src/version.c	2019-01-23 21:55:35.247616635 +0100
***************
*** 793,794 ****
--- 793,796 ----
  {   /* Add new patch number below this line */
+ /**/
+     798,
  /**/


-- 
       When danger reared its ugly head,
       He bravely turned his tail and fled
       Yes, Brave Sir Robin turned about
       And gallantly he chickened out
       Bravely taking to his feet
       He beat a very brave retreat
       Bravest of the brave Sir Robin
       Petrified of being dead
       Soiled his pants then brave Sir Robin
       Turned away and fled.
                 "Monty Python and the Holy Grail" PYTHON (MONTY) PICTURES LTD

 /// Bram Moolenaar -- Bram@Moolenaar.net -- http://www.Moolenaar.net   \\\
///        sponsor Vim, vote for features -- http://www.Vim.org/sponsor/ \\\
\\\  an exciting new programming language -- http://www.Zimbu.org        ///
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