GP-6248 fix text in title bar of search for encoded strings dialog

if selection does not have addresses, or if address map is empty, don't
show "null - null".

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/strings/EncodedStringsDialog.java

@@ -1103,9 +1103,11 @@ public class EncodedStringsDialog extends DialogComponentProvider {
 	}
 
 	private static String makeTitleString(AddressSetView addrs) {
-		return "Search For Encoded Strings - %s (%s - %s)".formatted(
-			formatLength(addrs.getNumAddresses(), "addresses"), addrs.getMinAddress(),
-			addrs.getMaxAddress());
+		String addrRangeStr = !addrs.isEmpty()
+				? "(%s - %s)".formatted(addrs.getMinAddress(), addrs.getMaxAddress())
+				: "";
+		return "Search For Encoded Strings - %s %s"
+				.formatted(formatLength(addrs.getNumAddresses(), "addresses"), addrRangeStr);
 	}
 
 	private static boolean charsetExists(String charsetName) {

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/strings/EncodedStringsPlugin.java

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -113,7 +113,7 @@ public class EncodedStringsPlugin extends ProgramPlugin {
 	}
 
 	private void showSearchForEncodedStrings(NavigatableActionContext lac) {
-		AddressSetView addrs = lac.hasSelection()
+		AddressSetView addrs = lac.hasSelection() && !lac.getSelection().isEmpty()
 				? lac.getSelection()
 				: lac.getProgram().getMemory().getAllInitializedAddressSet();
 		EncodedStringsDialog dlg = new EncodedStringsDialog(this, lac.getProgram(), addrs);