Bug 1187124 - Refer to $ANDROID_VERSION "... -ge 18" only when it is …

…a non-empty string. r=gps

--HG--
extra : rebase_source : 7e29fbc1e71ae5a639a194293450849090a29bc4

configure.in

@@ -5389,11 +5389,15 @@ if test -n "$MOZ_FMP4"; then
     MOZ_EME=1
 fi;
 
-if test "$MOZ_WIDGET_TOOLKIT" = "gonk" -a -n "$MOZ_FMP4" -a "$ANDROID_VERSION" -ge "18"; then
-    MOZ_GONK_MEDIACODEC=1
-    AC_SUBST(MOZ_GONK_MEDIACODEC)
+if test x"$MOZ_WIDGET_TOOLKIT" = x"gonk" -a -n "$MOZ_FMP4" -a -n "$ANDROID_VERSION"; then
+    # we now know for sure that $ANDROID_VERSION is not an empty string!
+    if test "$ANDROID_VERSION" -ge "18"; then
+        MOZ_GONK_MEDIACODEC=1
+        AC_SUBST(MOZ_GONK_MEDIACODEC)
+    fi
 fi
 
+
 dnl ========================================================
 dnl = EME support
 dnl ========================================================