id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
12799,Crash occurs inside fiber inside sscanf on Android,Lev Sch <zorechfan@…>,olli,"I started migrating from boost_1_62_0 to boost_1_63_0.

Migration failed: application crashed (no changes in my code).

I have constructed a minimal example that leads to crash. The test (boostTest.cpp file):

{{{
#include <cassert>
#include <android/log.h>
#include <boost/context/all.hpp>

#define TRACE(...) __android_log_print(ANDROID_LOG_DEBUG, ""boostTest"", __VA_ARGS__)

void callSscanf()
{
  TRACE(""callSscanf begin"");
  TRACE(""callSscanf line=%d"",__LINE__);
  if ( true ) {
    int n1=0;
    int n2=0;
    sscanf(""1 23"", ""%d %d"", &n1,&n2);
    assert(n1==1);
    assert(n2==23);
  }
  TRACE(""callSscanf line=%d"",__LINE__);
  if(true) {
    int n1=0;
    int n2=0;
    sscanf(""1 jjj 23"", ""%d %*[j] %d"", &n1,&n2);
    assert(n1==1);
    assert(n2==23);
  }
  TRACE(""callSscanf end"");
}

void FiberProc(void* arg)
{
  TRACE(""FiberProc begin"");
  boost::context::execution_context& mainCtx = *((boost::context::execution_context*)arg);
  callSscanf();
  mainCtx();
  TRACE(""FiberProc unreachable!!!"");
  assert(false); // not reachable
}

void boostContextTest()
{
  TRACE(""boostContextTest start"");
  {
    TRACE(""boostContextTest calling WITHOUT fiber"");
    callSscanf();
  }
  {
    TRACE(""boostContextTest calling WITH fiber"");
    boost::context::execution_context mainCtx(boost::context::execution_context::current());
    boost::context::execution_context childCtx(&FiberProc);
    childCtx(&mainCtx);
  }
  
  TRACE(""boostContextTest end"");
}

}}}
",Bugs,closed,To Be Determined,context,Boost 1.63.0,Problem,worksforme,,