fixed search term parser for empty terms

1 files changed, 18 insertions, 2 deletions

diff --git a/src/main/java/de/pixart/messenger/utils/FtsUtils.java b/src/main/java/de/pixart/messenger/utils/FtsUtils.java
index 86eeeeeaf..c6870d07e 100644
--- a/src/main/java/de/pixart/messenger/utils/FtsUtils.java
+++ b/src/main/java/de/pixart/messenger/utils/FtsUtils.java
@@ -44,10 +44,10 @@ public class FtsUtils {
             if (part.isEmpty()) {
                 continue;
             }
-            final String cleaned = part.substring(getStartIndex(part), getEndIndex(part) + 1);
+            final String cleaned = clean(part);
             if (isKeyword(cleaned)) {
                 term.add(part);
-            } else {
+            } else if (!cleaned.isEmpty()) {
                 term.add(cleaned);
             }
         }
@@ -76,9 +76,13 @@ public class FtsUtils {
     }
 
     private static int getStartIndex(String term) {
+        int length = term.length();
         int index = 0;
         while (term.charAt(index) == '*') {
             ++index;
+            if (index >= length) {
+                break;
+            }
         }
         return index;
     }
@@ -87,8 +91,20 @@ public class FtsUtils {
         int index = term.length() - 1;
         while (term.charAt(index) == '*') {
             --index;
+            if (index < 0) {
+                break;
+            }
         }
         return index;
     }
 
+    private static String clean(String input) {
+        int begin = getStartIndex(input);
+        int end = getEndIndex(input);
+        if (begin > end) {
+            return "";
+        } else {
+            return input.substring(begin, end + 1);
+        }
+    }
 }
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