[UI] WASM memory out of bounds crash when opening some JSON traces

[cphlipot1]

Currently crashes on autopush (V48.1), but not on canary or stable (V47) when opening certain JSON traces

This works fine with some traces bundled in perfetto's test/data folder like "test/data/sfgate.json" but crashes with others like "test/data/v8-samples.json"

UI: https://ui.perfetto.dev/v48.1-fffb94e33

RuntimeError: memory access out of bounds @ perfetto::trace_processor::StringPool::Get(perfetto::trace_processor::StringPool::Id) const
 - perfetto::trace_processor::StringPool::Get(perfetto::trace_processor::StringPool::Id) const (wasm://wasm/0241f9a6:wasm-function[1691]:0x16bac4)
 - perfetto::trace_processor::ColumnLegacy::GetAtIdx(unsigned int) const (wasm://wasm/0241f9a6:wasm-function[5042]:0x34896e)
 - perfetto::trace_processor::DbSqliteModule::Column(sqlite3_vtab_cursor*, sqlite3_context*, int) (wasm://wasm/0241f9a6:wasm-function[5067]:0x34d9d1)
 - sqlite3VdbeExec (wasm://wasm/0241f9a6:wasm-function[623]:0x50438)
 - sqlite3_step (wasm://wasm/0241f9a6:wasm-function[614]:0x4ae67)
 - perfetto::trace_processor::SqliteEngine::PreparedStatement::Step() (wasm://wasm/0241f9a6:wasm-function[5124]:0x353b02)
 - perfetto::trace_processor::PerfettoSqlEngine::ExecuteUntilLastStatement(perfetto::trace_processor::SqlSource) (wasm://wasm/0241f9a6:wasm-function[4957]:0x33a1ab)
 - perfetto::trace_processor::TraceProcessorImpl::ExecuteQuery(std::__2::basic_string<char, std::__2::char_traits<char>, std::__2::allocator<char> > const&) (wasm://wasm/0241f9a6:wasm-function[257]:0x172ac)
 - perfetto::trace_processor::Rpc::ParseRpcRequest(unsigned char const*, unsigned long) (wasm://wasm/0241f9a6:wasm-function[6286]:0x429ce7)
 - perfetto::trace_processor::Rpc::OnRpcRequest(void const*, unsigned long) (wasm://wasm/0241f9a6:wasm-function[6285]:0x427f14)
 -  (stderr: )
 - Loading trace 21.09 MB (26.0 MB/s)

Trace: not available (FILE). Provide repro steps.
UA: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36
Referrer: 

How to reproduce

Can easily be reproduced by opening the v8-samples.json included with Perfetto's test data.

./tools/install-build-deps
./tools/open_trace_in_ui test/data/v8-samples.json

Crash will automatically appear while the UI is loading the trace

[LalitMaganti]

Investigating. Strange because we use that trace in our all our automated testing and nothing is crashing. Maybe it's some specific query which is at fault?

[hahnicity]

We have at least 3 users now across our organization who are running into the issue.

[LalitMaganti]

I can reproduce, bisecting to find the commit at fault. Should have the fix shortly.

[LalitMaganti]

Will be fixed when https://r.android.com/3311138 lands.