patch 8.0.0876: backslashes and wildcards in backticks don't work

Problem:    MS-Windows: Backslashes and wildcards in backticks don't work.
Solution:   Do not handle backslashes inside backticks in the wrong place.
            (Yasuhiro Matsumoto, closes #1942)

src/os_mswin.c

@@ -450,6 +450,15 @@ slash_adjust(char_u *p)
 {
     if (path_with_url(p))
 	return;
+
+    if (*p == '`')
+    {
+	/* don't replace backslash in backtick quoted strings */
+	int len = STRLEN(p);
+	if (len > 2 && *(p + len - 1) == '`')
+	    return;
+    }
+
     while (*p)
     {
 	if (*p == psepcN)

src/os_win32.c

@@ -7004,6 +7004,8 @@ fix_arg_enc(void)
 	str = utf16_to_enc(ArglistW[idx], NULL);
 	if (str != NULL)
 	{
+	    int literal = used_file_literal;
+
 #ifdef FEAT_DIFF
 	    /* When using diff mode may need to concatenate file name to
 	     * directory name.  Just like it's done in main(). */
@@ -7025,7 +7027,15 @@ fix_arg_enc(void)
 	    if (used_file_literal)
 		buf_set_name(fnum_list[i], str);
 
-	    alist_add(&global_alist, str, used_file_literal ? 2 : 0);
+	    /* Check backtick literal. backtick literal is already expanded in
+	     * main.c, so this part add str as literal. */
+	    if (literal == FALSE)
+	    {
+		int len = STRLEN(str);
+		if (len > 2 && *str == '`' && *(str + len - 1) == '`')
+		    literal = TRUE;
+	    }
+	    alist_add(&global_alist, str, literal ? 2 : 0);
 	}
     }
 

src/version.c

@@ -769,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    876,
 /**/
     875,
 /**/