patch 9.0.0016: comparing line pointer for 'breakindent' is not reliable

Problem:    Comparing line pointer for 'breakindent' is not reliable.
Solution:   Make a copy of the line.

src/indent.c

@@ -924,7 +924,8 @@ get_breakindent_win(
 {
     static int	    prev_indent = 0;	// cached indent value
     static long	    prev_ts     = 0L;	// cached tabstop value
-    static char_u   *prev_line = NULL;	// cached pointer to line
+    static int	    prev_fnum   = 0;	// cached buffer number
+    static char_u   *prev_line  = NULL;	// cached copy of "line"
     static varnumber_T prev_tick = 0;   // changedtick of cached value
 # ifdef FEAT_VARTABS
     static int      *prev_vts = NULL;   // cached vartabs values
@@ -941,21 +942,28 @@ get_breakindent_win(
 						? number_width(wp) + 1 : 0);
 
     // used cached indent, unless
-    // - line pointer changed
+    // - buffer changed
     // - 'tabstop' changed
+    // - buffer was changed
     // - 'briopt_list changed' changed or
     // - 'formatlistpattern' changed
-    if (prev_line != line || prev_ts != wp->w_buffer->b_p_ts
+    // - line changed
+    // - 'vartabs' changed
+    if (prev_fnum != wp->w_buffer->b_fnum
+	    || prev_ts != wp->w_buffer->b_p_ts
 	    || prev_tick != CHANGEDTICK(wp->w_buffer)
 	    || prev_listopt != wp->w_briopt_list
-	    || (prev_flp == NULL
-		|| (STRCMP(prev_flp, get_flp_value(wp->w_buffer)) != 0))
+	    || prev_flp == NULL
+	    || STRCMP(prev_flp, get_flp_value(wp->w_buffer)) != 0
+	    || prev_line == NULL || STRCMP(prev_line, line) != 0
 # ifdef FEAT_VARTABS
 	    || prev_vts != wp->w_buffer->b_p_vts_array
 # endif
 	)
     {
-	prev_line = line;
+	prev_fnum = wp->w_buffer->b_fnum;
+	vim_free(prev_line);
+	prev_line = vim_strsave(line);
 	prev_ts = wp->w_buffer->b_p_ts;
 	prev_tick = CHANGEDTICK(wp->w_buffer);
 # ifdef FEAT_VARTABS

src/testdir/test_breakindent.vim

@@ -716,9 +716,6 @@ func Test_breakindent20_cpo_n_nextpage()
 endfunc
 
 func Test_breakindent20_list()
-  " FIXME - this should not matter
-  call test_override('alloc_lines', 0)
-
   call s:test_windows('setl breakindent breakindentopt= linebreak')
   " default:
   call setline(1, ['  1.  Congress shall make no law',
@@ -802,12 +799,12 @@ func Test_breakindent20_list()
   call s:compare_lines(expect, lines)
   " check formatlistpat indent with different list levels
   let &l:flp = '^\s*\*\+\s\+'
-  redraw!
   %delete _
   call setline(1, ['* Congress shall make no law',
         \ '*** Congress shall make no law',
         \ '**** Congress shall make no law'])
   norm! 1gg
+  redraw!
   let expect = [
 	\ "* Congress shall    ",
 	\ "  make no law       ",
@@ -835,9 +832,6 @@ func Test_breakindent20_list()
   let lines = s:screen_lines2(1, 6, 20)
   call s:compare_lines(expect, lines)
   call s:close_windows('set breakindent& briopt& linebreak& list& listchars& showbreak&')
-
-  " FIXME - this should not matter
-  call test_override('alloc_lines', 1)
 endfunc
 
 " The following used to crash Vim. This is fixed by 8.2.3391.
@@ -881,9 +875,6 @@ func Test_cursor_position_with_showbreak()
 endfunc
 
 func Test_no_spurious_match()
-  " FIXME - fails under valgrind - this should not matter - timing issue?
-  call test_override('alloc_lines', 0)
-
   let s:input = printf('- y %s y %s', repeat('x', 50), repeat('x', 50))
   call s:test_windows('setl breakindent breakindentopt=list:-1 formatlistpat=^- hls')
   let @/ = '\%>3v[y]'
@@ -893,8 +884,6 @@ func Test_no_spurious_match()
   " cleanup
   set hls&vim
   bwipeout!
-  " FIXME - this should not matter
-  call test_override('alloc_lines', 1)
 endfunc
 
 func Test_no_extra_indent()

src/version.c

@@ -735,6 +735,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    16,
 /**/
     15,
 /**/