fix ASAN in SharedStringPool

regression from
    commit 3581f1d71ae0d431ba28c0f3b7b263ff6212ce7b
    optimize SharedStringPool::purge() and fix tests

which results in us potentially de-referencing an already de-allocated
OUString object in the first loop in purge().

So switch to a different strategy, which only needs one data structure,
instead of two.

Change-Id: Iaac6beda48459643afdb7b14ce7d39d68a93339c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/95226
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 20 insertions, 5 deletions

diff --git a/svl/qa/unit/svl.cxx b/svl/qa/unit/svl.cxx
index 194dc550c278..c32017f7aea6 100644
--- a/svl/qa/unit/svl.cxx
+++ b/svl/qa/unit/svl.cxx
@@ -60,6 +60,7 @@ public:
     void testSharedString();
     void testSharedStringPool();
     void testSharedStringPoolPurge();
+    void testSharedStringPoolPurgeBug1();
     void testFdo60915();
     void testI116701();
     void testTdf103060();
@@ -77,6 +78,7 @@ public:
     CPPUNIT_TEST(testSharedString);
     CPPUNIT_TEST(testSharedStringPool);
     CPPUNIT_TEST(testSharedStringPoolPurge);
+    CPPUNIT_TEST(testSharedStringPoolPurgeBug1);
     CPPUNIT_TEST(testFdo60915);
     CPPUNIT_TEST(testI116701);
     CPPUNIT_TEST(testTdf103060);
@@ -376,30 +378,30 @@ void Test::testSharedStringPoolPurge()
     std::optional<svl::SharedString> pStr3 = aPool.intern("ANDY");
     std::optional<svl::SharedString> pStr4 = aPool.intern("Bruce");
 
-    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(4), aPool.getCount());
+    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(5), aPool.getCount());
     CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(2), aPool.getCountIgnoreCase());
 
     // This shouldn't purge anything.
     aPool.purge();
-    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(4), aPool.getCount());
+    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(5), aPool.getCount());
     CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(2), aPool.getCountIgnoreCase());
 
     // Delete one heap string object, and purge. That should purge one string.
     pStr1.reset();
     aPool.purge();
-    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(3), aPool.getCount());
+    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(4), aPool.getCount());
     CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(2), aPool.getCountIgnoreCase());
 
     // Nothing changes, because the upper-string is still in the map
     pStr3.reset();
     aPool.purge();
-    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(3), aPool.getCount());
+    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(4), aPool.getCount());
     CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(2), aPool.getCountIgnoreCase());
 
     // Again.
     pStr2.reset();
     aPool.purge();
-    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(1), aPool.getCount());
+    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(2), aPool.getCount());
     CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(1), aPool.getCountIgnoreCase());
 
     // Delete 'Bruce' and purge.
@@ -409,6 +411,19 @@ void Test::testSharedStringPoolPurge()
     CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(0), aPool.getCountIgnoreCase());
 }
 
+void Test::testSharedStringPoolPurgeBug1()
+{
+    // We had a bug where, if we had two strings that mapped to the same uppercase string,
+    // purge() would de-reference a dangling pointer and consequently cause an ASAN failure.
+    SvtSysLocale aSysLocale;
+    svl::SharedStringPool aPool(*aSysLocale.GetCharClassPtr());
+    aPool.intern("Andy");
+    aPool.intern("andy");
+    aPool.purge();
+    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(0), aPool.getCount());
+    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(0), aPool.getCountIgnoreCase());
+}
+
 void Test::checkPreviewString(SvNumberFormatter& aFormatter,
                               const OUString& sCode,
                               double fPreviewNumber,