improve filtering by filetype navigator.

The used url-filter for filetype doesn't require ".ext" resulting in too many matches,
add a sort-out filter for RWI results.

source/net/yacy/search/query/QueryParams.java

@@ -205,7 +205,7 @@ public final class QueryParams {
             String protocolfilter = modifier.protocol == null ? ".*" : modifier.protocol;
             String defaulthostprefix = modifier.protocol == null ? "www" : modifier.protocol;
             String hostfilter = modifier.sitehost == null && tld == null ? ".*" : modifier.sitehost == null ? ".*\\." + tld : modifier.sitehost.startsWith(defaulthostprefix + ".") ? "(" + defaulthostprefix + "\\.)?" + modifier.sitehost.substring(4) : "(" + defaulthostprefix + "\\.)?" + modifier.sitehost;
-            String filefilter = modifier.filetype == null ? ".*" : ".*" + modifier.filetype + ".*";
+            String filefilter = modifier.filetype == null ? ".*" : ".*" + modifier.filetype + ".*"; // TODO: should be ".ext" but while/comment above suggests not -> add filetype contrain pullOneFilteredFromRWI()
             String filter = protocolfilter + "..." + hostfilter + "." + filefilter;
             if (!filter.equals(".*....*..*")) {
                 Pattern r = Pattern.compile("(\\.|(\\.\\*))\\.\\*");

source/net/yacy/search/query/SearchEvent.java

@@ -1159,6 +1159,13 @@ public final class SearchEvent {
                 continue;
             }
 
+            // check modifier constraint filetype (using fileextension)
+            if (this.query.modifier.filetype != null && !this.query.modifier.filetype.equals(ext)) {
+                if (log.isFine()) log.fine("dropped RWI: file type constraint = " + this.query.modifier.filetype);
+                if (page.word().local()) this.local_rwi_available.decrementAndGet(); else this.remote_rwi_available.decrementAndGet();
+                continue;
+            }
+
             // check modifier constraint (language)
             // TODO: : page.language() never null but defaults to "en" (may cause false drop of result)
             if (this.query.modifier.language != null && !this.query.modifier.language.equals(page.language())) {