8215291: Broken links when generating from project without modules

Backport-of: cb55317

Author: basil

src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/resources/search.js

@@ -50,7 +50,7 @@ function getURLPrefix(ui) {
             return ui.item.m + slash;
         } else if ((ui.item.category === catTypes && ui.item.p) || ui.item.category === catMembers) {
             $.each(packageSearchIndex, function(index, item) {
-                if (ui.item.p == item.l) {
+                if (item.m && ui.item.p == item.l) {
                     urlPrefix = item.m + slash;
                 }
             });

test/langtools/jdk/javadoc/doclet/testSearch/TestSearch.java

@@ -644,7 +644,7 @@ void checkSearchJS() {
                 + "            return ui.item.m + slash;\n"
                 + "        } else if ((ui.item.category === catTypes && ui.item.p) || ui.item.category === catMembers) {\n"
                 + "            $.each(packageSearchIndex, function(index, item) {\n"
-                + "                if (ui.item.p == item.l) {\n"
+                + "                if (item.m && ui.item.p == item.l) {\n"
                 + "                    urlPrefix = item.m + slash;\n"
                 + "                }\n"
                 + "            });\n"