base.bbclass: fix PACKAGECONFIG handling code

PACKAGECONFIG flag code only handles that when it has 3 or 4 items in flag,
it may have a stale data if some flags doesn't need DEPENDS and RDEPENDS.

(From OE-Core rev: 884cab0428cff2ffd070b6f36b688ca9851fbe43)

Signed-off-by: Yao Zhao <yao.zhao@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/base.bbclass

@@ -382,20 +382,19 @@ python () {
             if flag == "defaultval":
                 continue
             items = flagval.split(",")
-            if len(items) == 3:
+            num = len(items)
-                enable, disable, depend = items
+            if num > 4:
-                rdepend = ""
+                bb.error("Only enable,disable,depend,rdepend can be specified!")
-            elif len(items) == 4:
+
-                enable, disable, depend, rdepend = items
             if flag in pkgconfig:
-                if depend:
+                if num >= 3 and items[2]:
-                    extradeps.append(depend)
+                    extradeps.append(items[2])
-                if rdepend:
+                if num >= 4 and items[3]:
-                    extrardeps.append(rdepend)
+                    extrardeps.append(items[3])
-                if enable:
+                if num >= 1 and items[0]:
-                    extraconf.append(enable)
+                    extraconf.append(items[0])
-            elif disable:
+            elif num >= 2 and items[1]:
-                    extraconf.append(disable)
+                    extraconf.append(items[1])
         appendVar('DEPENDS', extradeps)
         appendVar('RDEPENDS_${PN}', extrardeps)
         appendVar('EXTRA_OECONF', extraconf)