From 0be00b791ffa9e6d073a6626108fa763ac9d62bb Mon Sep 17 00:00:00 2001
From: Veloman Yunkan <veloman.yunkan@gmail.com>
Date: Sat, 11 Dec 2021 16:34:16 +0400
Subject: [PATCH] Searcher::add_reader() rejects duplicate readers

A O(N) linear search was added to `Searcher::add_reader()` deliberately.
This doesn't seem to be an operation that may lead to performance
problems.
---
 src/searcher.cpp  |  6 ++++++
 test/searcher.cpp | 16 +++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/searcher.cpp b/src/searcher.cpp
index 8fa77c391..51f16a7b3 100644
--- a/src/searcher.cpp
+++ b/src/searcher.cpp
@@ -94,6 +94,12 @@ bool Searcher::add_reader(Reader* reader)
   if (!reader->hasFulltextIndex()) {
       return false;
   }
+
+  for ( const Reader* const existing_reader : readers ) {
+    if ( existing_reader->getZimFilePath() == reader->getZimFilePath() )
+      return false;
+  }
+
   this->readers.push_back(reader);
   return true;
 }
diff --git a/test/searcher.cpp b/test/searcher.cpp
index a3569d959..735f4c373 100644
--- a/test/searcher.cpp
+++ b/test/searcher.cpp
@@ -5,6 +5,20 @@
 namespace kiwix
 {
 
+TEST(Searcher, add_reader) {
+  Reader reader1("./test/example.zim");
+  Reader reader2("./test/example.zim");
+  Reader reader3("./test/../test/example.zim");
+
+  Searcher searcher;
+  ASSERT_TRUE (searcher.add_reader(&reader1));
+  ASSERT_FALSE(searcher.add_reader(&reader1));
+  ASSERT_FALSE(searcher.add_reader(&reader2));
+
+  // equivalence of resolved paths is not checked by Searcher::add_reader
+  ASSERT_TRUE(searcher.add_reader(&reader3));
+}
+
 TEST(Searcher, search) {
   Reader reader("./test/example.zim");
 
@@ -64,4 +78,4 @@ TEST(Searcher, incrementalRange) {
   ASSERT_EQ(suggCount, 50);
 }
 
-}
\ No newline at end of file
+}