patch 8.2.1957: diff and cursorcolumn highlighting don't mix

Problem:    Diff and cursorcolumn highlighting don't mix.
Solution:   Fix condition for what attribute to use. (Christian Brabandt,
            closes #7258, closes #7260)
diff --git a/src/drawline.c b/src/drawline.c
index 82738f1..6b9cbc6 100644
--- a/src/drawline.c
+++ b/src/drawline.c
@@ -1873,6 +1873,7 @@
 			char_u	*prev_ptr, *p;
 			int	len;
 			hlf_T	spell_hlf = HLF_COUNT;
+
 			if (has_mbyte)
 			{
 			    prev_ptr = ptr - mb_l;
@@ -2778,10 +2779,14 @@
 	// Also highlight the 'colorcolumn' if 'breakindent' and/or 'showbreak'
 	// options are set
 	vcol_save_attr = -1;
-	if ((draw_state == WL_LINE ||
+	if (((draw_state == WL_LINE ||
 	     draw_state == WL_BRI ||
 	     draw_state == WL_SBR) && !lnum_in_visual_area
 		&& search_attr == 0 && area_attr == 0)
+# ifdef FEAT_DIFF
+			&& filler_todo <= 0
+# endif
+		)
 	{
 	    if (wp->w_p_cuc && VCOL_HLC == (long)wp->w_virtcol
 						 && lnum != wp->w_cursor.lnum)
diff --git a/src/testdir/dumps/Test_diff_cuc_01.dump b/src/testdir/dumps/Test_diff_cuc_01.dump
new file mode 100644
index 0000000..19c42f4
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_cuc_01.dump
@@ -0,0 +1,20 @@
+>a+0&#ffffff0@1| @34||+1&&| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0@1| @32
+|-+0#4040ff13#afffff255@36||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1|b+0#0000000#5fd7ff255@1| @32
+|c+0&#e0e0e08|c+0&#ffffff0| @34||+1&&| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0@1| @32
+|~+0#4040ff13&| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|[+3#0000000&|N|o| |N|a|m|e|]| |[|+|]| @5|1|,|1| @11|A|l@1| |[+1&&|N|o| |N|a|m|e|]| |[|+|]| @5|1|,|1| @11|A|l@1
+| +0&&@74
diff --git a/src/testdir/dumps/Test_diff_cuc_02.dump b/src/testdir/dumps/Test_diff_cuc_02.dump
new file mode 100644
index 0000000..80a296c
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_cuc_02.dump
@@ -0,0 +1,20 @@
+|a+0&#ffffff0>a| @34||+1&&| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0@1| @32
+|-+0#4040ff13#afffff255@36||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1|b+0#0000000#5fd7ff255@1| @32
+|c+0&#ffffff0|c+0&#e0e0e08| +0&#ffffff0@34||+1&&| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0@1| @32
+|~+0#4040ff13&| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|[+3#0000000&|N|o| |N|a|m|e|]| |[|+|]| @5|1|,|2| @11|A|l@1| |[+1&&|N|o| |N|a|m|e|]| |[|+|]| @5|1|,|2| @11|A|l@1
+| +0&&@74
diff --git a/src/testdir/dumps/Test_diff_cuc_03.dump b/src/testdir/dumps/Test_diff_cuc_03.dump
new file mode 100644
index 0000000..19a3c1f
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_cuc_03.dump
@@ -0,0 +1,20 @@
+|a+0&#e0e0e08|a+0&#ffffff0| @34||+1&&| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0@1| @32
+|-+0#4040ff13#afffff255@36||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1|b+0#0000000#5fd7ff255@1| @32
+>c+0&#ffffff0@1| @34||+1&&| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0@1| @32
+|~+0#4040ff13&| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|[+3#0000000&|N|o| |N|a|m|e|]| |[|+|]| @5|2|,|1| @11|A|l@1| |[+1&&|N|o| |N|a|m|e|]| |[|+|]| @5|3|,|1| @11|A|l@1
+| +0&&@74
diff --git a/src/testdir/dumps/Test_diff_cuc_04.dump b/src/testdir/dumps/Test_diff_cuc_04.dump
new file mode 100644
index 0000000..ba29893
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_cuc_04.dump
@@ -0,0 +1,20 @@
+|a+0&#ffffff0|a+0&#e0e0e08| +0&#ffffff0@34||+1&&| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0@1| @32
+|-+0#4040ff13#afffff255@36||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1|b+0#0000000#5fd7ff255@1| @32
+|c+0&#ffffff0>c| @34||+1&&| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0@1| @32
+|~+0#4040ff13&| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|[+3#0000000&|N|o| |N|a|m|e|]| |[|+|]| @5|2|,|2| @11|A|l@1| |[+1&&|N|o| |N|a|m|e|]| |[|+|]| @5|3|,|2| @11|A|l@1
+| +0&&@74
diff --git a/src/testdir/test_diffmode.vim b/src/testdir/test_diffmode.vim
index 770dde0..aba9c9a 100644
--- a/src/testdir/test_diffmode.vim
+++ b/src/testdir/test_diffmode.vim
@@ -1150,4 +1150,37 @@
   set ls&
 endfunc
 
+func Test_diff_filler_cursorcolumn()
+  CheckScreendump
+
+  let content =<< trim END
+    call setline(1, ['aa', 'bb', 'cc'])
+    vnew
+    call setline(1, ['aa', 'cc'])
+    windo diffthis
+    wincmd p
+    setlocal cursorcolumn foldcolumn=0
+    norm! gg0
+    redraw!
+  END
+  call writefile(content, 'Xtest_diff_cuc')
+  let buf = RunVimInTerminal('-S Xtest_diff_cuc', {})
+
+  call VerifyScreenDump(buf, 'Test_diff_cuc_01', {})
+
+  call term_sendkeys(buf, "l")
+  call term_sendkeys(buf, "\<C-l>")
+  call VerifyScreenDump(buf, 'Test_diff_cuc_02', {})
+  call term_sendkeys(buf, "0j")
+  call term_sendkeys(buf, "\<C-l>")
+  call VerifyScreenDump(buf, 'Test_diff_cuc_03', {})
+  call term_sendkeys(buf, "l")
+  call term_sendkeys(buf, "\<C-l>")
+  call VerifyScreenDump(buf, 'Test_diff_cuc_04', {})
+
+  " clean up
+  call StopVimInTerminal(buf)
+  call delete('Xtest_diff_cuc')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index 4c8579a..ca5a513 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1957,
+/**/
     1956,
 /**/
     1955,