patch 7.4.1751
Problem:    Crash when 'tagstack' is off. (Dominique Pelle)
Solution:   Fix it. (Hirohito Higashi)
diff --git a/src/tag.c b/src/tag.c
index 4224c6f..8f4495e 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -200,6 +200,14 @@
     {
 	use_tagstack = FALSE;
 	new_tag = TRUE;
+#if defined(FEAT_WINDOWS) && defined(FEAT_QUICKFIX)
+	if (g_do_tagpreview != 0)
+	{
+	    vim_free(ptag_entry.tagname);
+	    if ((ptag_entry.tagname = vim_strsave(tag)) == NULL)
+		goto end_do_tag;
+	}
+#endif
     }
     else
     {
diff --git a/src/testdir/test_alot.vim b/src/testdir/test_alot.vim
index 5637a8e..cb37771 100644
--- a/src/testdir/test_alot.vim
+++ b/src/testdir/test_alot.vim
@@ -27,6 +27,7 @@
 source test_statusline.vim
 source test_syn_attr.vim
 source test_tabline.vim
+source test_tagjump.vim
 source test_timers.vim
 source test_undolevels.vim
 source test_unlet.vim
diff --git a/src/version.c b/src/version.c
index 695d0b7..7918d99 100644
--- a/src/version.c
+++ b/src/version.c
@@ -749,6 +749,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1751,
+/**/
     1750,
 /**/
     1749,