Revert "freebusy: trim shared_ptr from internal API"

This reverts commit bcf55c2.

ptz_component can be an empty std::optional; as a result,
ptz_component->component_list is invalid.

==22636==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000010
==22636==The signal is caused by a READ memory access.
==22636==Hint: address points to the zero page.
f1 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::c_str() const /usr/include/c++/7/bits/basic_string.h:2281
f2 ical_utc_to_datetime(ical_component const*, long, ICAL_TIME*) lib/email/ical.cpp:1503
f3 recurrencepattern_to_rrule tools/freebusy.cpp:266
f4 find_recurrence_times tools/freebusy.cpp:292
f5 get_freebusy tools/freebusy.cpp:759
f6 main tools/freebusy.cpp:1023

Fixes: gromox-1.28-218-gbcf55c2c4

tools/freebusy.cpp

@@ -185,7 +185,7 @@ static std::optional<ical_component> tzstruct_to_vtimezone(int year,
  return {};
 }
 
-static BOOL recurrencepattern_to_rrule(const ical_component &tzcom,
+static BOOL recurrencepattern_to_rrule(const ical_component *tzcom,
  time_t whole_start_time, const APPOINTMENT_RECUR_PAT *apr,
  ICAL_RRULE *pirrule) try
 {
@@ -263,7 +263,7 @@ static BOOL recurrencepattern_to_rrule(const ical_component &tzcom,
  piline->append_value("COUNT", std::to_string(apr->recur_pat.occurrencecount));
  } else if (apr->recur_pat.endtype == ENDTYPE_AFTER_DATE) {
  char tmp_buff[1024];
- ical_utc_to_datetime(&tzcom, rop_util_rtime_to_unix(apr->recur_pat.enddate + apr->starttimeoffset), &itime);
+ ical_utc_to_datetime(tzcom, rop_util_rtime_to_unix(apr->recur_pat.enddate + apr->starttimeoffset), &itime);
  sprintf_dtutc(tmp_buff, std::size(tmp_buff), itime);
  piline->append_value("UNTIL", tmp_buff);
  }
@@ -273,14 +273,14 @@ static BOOL recurrencepattern_to_rrule(const ical_component &tzcom,
  return FALSE;
  piline->append_value("WKST", wd);
  }
- return ical_parse_rrule(&tzcom, whole_start_time,
+ return ical_parse_rrule(tzcom, whole_start_time,
  &piline->value_list, pirrule) ? TRUE : false;
 } catch (const std::bad_alloc &) {
  fprintf(stderr, "E-2093: ENOMEM\n");
  return false;
 }
 
-static BOOL find_recurrence_times(ical_component &tzcom,
+static BOOL find_recurrence_times(const ical_component *tzcom,
  time_t whole_start_time, const APPOINTMENT_RECUR_PAT *apr,
  time_t start_time, time_t end_time, std::list<event_node> &plist)
 {
@@ -295,7 +295,7 @@ static BOOL find_recurrence_times(ical_component &tzcom,
  plist.clear();
  do {
  auto itime = irrule.instance_itime;
- ical_itime_to_utc(&tzcom, itime, &tmp_time);
+ ical_itime_to_utc(tzcom, itime, &tmp_time);
  if (tmp_time < start_time)
  continue;
  ical_itime_to_utc(NULL, itime, &tmp_time1);
@@ -318,15 +318,15 @@ static BOOL find_recurrence_times(ical_component &tzcom,
  tmp_time = rop_util_rtime_to_unix(apr->pexceptioninfo[i].startdatetime);
  ICAL_TIME itime;
  ical_utc_to_datetime(NULL, tmp_time, &itime);
- ical_itime_to_utc(&tzcom, itime, &tmp_time);
+ ical_itime_to_utc(tzcom, itime, &tmp_time);
  if (tmp_time < start_time || tmp_time > end_time)
  continue;
  plist.emplace_back();
  auto pevnode = &plist.back();
  pevnode->start_time = tmp_time;
  tmp_time = rop_util_rtime_to_unix(apr->pexceptioninfo[i].enddatetime);
  ical_utc_to_datetime(NULL, tmp_time, &itime);
- ical_itime_to_utc(&tzcom, itime, &tmp_time);
+ ical_itime_to_utc(tzcom, itime, &tmp_time);
  pevnode->end_time = tmp_time;
  pevnode->pexception = apr->pexceptioninfo + i;
  pevnode->pex_exception = apr->pextendedexception + i;
@@ -756,7 +756,8 @@ static BOOL get_freebusy(const char *dir)
  if (ext_pull.g_apptrecpat(&apprecurr) != EXT_ERR_SUCCESS)
  continue;
  std::list<event_node> event_list;
- if (!find_recurrence_times(*ptz_component, whole_start_time,
+ if (!find_recurrence_times(ptz_component.has_value() ?
+ &ptz_component.value() : nullptr, whole_start_time,
  &apprecurr, g_start_time, g_end_time, event_list))
  continue;
  while (event_list.size() > 0) {