From 3c346b94096eb7e1eef7546723476732a3ac7990 Mon Sep 17 00:00:00 2001
From: Simon Redman <simon@ergotech.com>
Date: Fri, 7 Jun 2019 16:39:05 -0600
Subject: [PATCH] Block matching empty phone numbers

---
 smsapp/smshelper.cpp    |  5 +++++
 tests/testsmshelper.cpp | 14 ++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/smsapp/smshelper.cpp b/smsapp/smshelper.cpp
index 1ceb378f8..a20c0d720 100644
--- a/smsapp/smshelper.cpp
+++ b/smsapp/smshelper.cpp
@@ -28,6 +28,11 @@ Q_LOGGING_CATEGORY(KDECONNECT_SMS_SMSHELPER, "kdeconnect.sms.smshelper")
 
 bool SmsHelper::isPhoneNumberMatchCanonicalized(const QString& canonicalPhone1, const QString& canonicalPhone2)
 {
+    if (canonicalPhone1.isEmpty() || canonicalPhone2.isEmpty()) {
+        // The empty string is not a valid phone number so does not match anything
+        return false;
+    }
+
     // To decide if a phone number matches:
     // 1. Are they similar lengths? If two numbers are very different, probably one is junk data and should be ignored
     // 2. Is one a superset of the other? Phone number digits get more specific the further towards the end of the string,
diff --git a/tests/testsmshelper.cpp b/tests/testsmshelper.cpp
index 56e6cb632..89a723fe3 100644
--- a/tests/testsmshelper.cpp
+++ b/tests/testsmshelper.cpp
@@ -48,6 +48,7 @@ private Q_SLOTS:
     void testDifferentPhoneNumbers1();
     void testDifferentPhoneNumbers2();
     void testAllZeros();
+    void testEmptyInput();
 };
 
 /**
@@ -254,5 +255,18 @@ void SmsHelperTest::testAllZeros()
     QCOMPARE(canonicalized.length(), zeros.length());
 }
 
+/**
+ * An empty string is not a valid phone number and should not match anything
+ */
+void SmsHelperTest::testEmptyInput()
+{
+    const QString& empty = QLatin1String("");
+    const QString& shortCode = QLatin1String("44455");
+    const QString& realNumber = QLatin1String("12223334444");
+
+    QVERIFY2(!SmsHelper::isPhoneNumberMatch(empty, shortCode), "The empty string matched a shortcode phone number");
+    QVERIFY2(!SmsHelper::isPhoneNumberMatch(empty, realNumber), "The empty string matched a real phone number");
+}
+
 QTEST_MAIN(SmsHelperTest);
 #include "testsmshelper.moc"