patch 8.2.4899: with latin1 encoding CTRL-W might go before the cmdline

Problem:    With latin1 encoding CTRL-W might go before the start of the
            command line.
Solution:   Check already being at the start of the command line.
diff --git a/src/ex_getln.c b/src/ex_getln.c
index a97024b..7020f51 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -1082,10 +1082,13 @@
 	{
 	    while (p > ccline.cmdbuff && vim_isspace(p[-1]))
 		--p;
-	    i = vim_iswordc(p[-1]);
-	    while (p > ccline.cmdbuff && !vim_isspace(p[-1])
-		    && vim_iswordc(p[-1]) == i)
-		--p;
+	    if (p > ccline.cmdbuff)
+	    {
+		i = vim_iswordc(p[-1]);
+		while (p > ccline.cmdbuff && !vim_isspace(p[-1])
+			&& vim_iswordc(p[-1]) == i)
+		    --p;
+	    }
 	}
 	else
 	    --p;
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 474638f..5a849f7 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -773,6 +773,9 @@
 
     call feedkeys(":abc def\<S-Left>\<C-U>\<C-B>\"\<CR>", 'tx')
     call assert_equal('"def', @:, e)
+
+    " This was going before the start in latin1.
+    call feedkeys(": \<C-W>\<CR>", 'tx')
   endfor
 
   let &encoding = encoding_save
diff --git a/src/version.c b/src/version.c
index 201d26f..05888c7 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4899,
+/**/
     4898,
 /**/
     4897,