patch 8.2.3265: smartcase does not work correctly in very magic pattern

Problem:    Smartcase does not work correctly in very magic pattern.
Solution:   Take the magicness into account when skipping over regexp items.
            (Christian Brabandt, closes #8682, closes #7845)
diff --git a/src/search.c b/src/search.c
index 920c68c..4396651 100644
--- a/src/search.c
+++ b/src/search.c
@@ -430,6 +430,10 @@
 pat_has_uppercase(char_u *pat)
 {
     char_u *p = pat;
+    magic_T magic_val = MAGIC_ON;
+
+    // get the magicness of the pattern
+    (void)skip_regexp_ex(pat, NUL, magic_isset(), NULL, NULL, &magic_val);
 
     while (*p != NUL)
     {
@@ -441,7 +445,7 @@
 		return TRUE;
 	    p += l;
 	}
-	else if (*p == '\\')
+	else if (*p == '\\' && magic_val == MAGIC_ON)
 	{
 	    if (p[1] == '_' && p[2] != NUL)  // skip "\_X"
 		p += 3;
@@ -452,6 +456,11 @@
 	    else
 		p += 1;
 	}
+	else if ((*p == '%' || *p == '_') && magic_val == MAGIC_ALL)
+	{
+	    if (p[1] != NUL)  // skip "_X" and %X
+		p += 2;
+	}
 	else if (MB_ISUPPER(*p))
 	    return TRUE;
 	else