tdf#162574 sc HTML paste: handle not well-formed json for td data-sheets-value

Regression from commit f5f6db55a5938f37a1c136be904ad7f10a3438ef
(tdf#159483 sc HTML paste: handle data-sheets-value here, too,
2024-02-08), in case the HTML markup is like:

<td data-sheets-value="... garbage ...">

then just ignore it, as if the attribute would be missing. We're only
interested in the case where it contains well-formed JSON.

Change-Id: Id625205e56ae2bfe05a26296a1a0f3abf6d5a4f2
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/172452
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

sc/qa/filter/html/data/bad-json.html

@@ -0,0 +1,4 @@
+<meta http-equiv="content-type" content="text/html; charset=utf-8"><div><table>
+<tbody>
+<tr><td data-sheets-value="{"></td></tr>
+</tbody></table></div>

sc/qa/filter/html/html.cxx

@@ -85,6 +85,21 @@ CPPUNIT_TEST_FIXTURE(Test, testPasteTdAsText)
     CPPUNIT_ASSERT_EQUAL(CELLTYPE_STRING, eCellType);
 }
 
+CPPUNIT_TEST_FIXTURE(Test, testPasteBadJson)
+{
+    createScDoc();
+
+    // Just care we don't crash on not-well-formed JSON:
+    ScDocument* pDoc = getScDoc();
+    ScAddress aCellPos(/*nColP=*/0, /*nRowP=*/0, /*nTabP=*/0);
+    ScImportExport aImporter(*pDoc, aCellPos);
+    SvFileStream aFile(createFileURL(u"bad-json.html"), StreamMode::READ);
+    SvMemoryStream aMemory;
+    aMemory.WriteStream(aFile);
+    aMemory.Seek(0);
+    CPPUNIT_ASSERT(aImporter.ImportStream(aMemory, OUString(), SotClipboardFormatId::HTML));
+}
+
 CPPUNIT_TEST_FIXTURE(Test, testPasteTdAsBools)
 {
     // Given an empty document:

sc/source/filter/html/htmlpars.cxx

@@ -84,7 +84,15 @@ void ParseDataSheetsValue(const OUString& rDataSheetsValue, std::optional<OUStri
     const char* pEncodedOption = aEncodedOption.getStr();
     std::stringstream aStream(pEncodedOption);
     boost::property_tree::ptree aTree;
-    boost::property_tree::read_json(aStream, aTree);
+    try
+    {
+        boost::property_tree::read_json(aStream, aTree);
+    }
+    catch (const std::exception&)
+    {
+        SAL_WARN("sc", "ParseDataSheetsValue: not well-formed json");
+        return;
+    }
     // The "1" key describes the original data type.
     auto it = aTree.find("1");
     if (it != aTree.not_found())