BUG#39934: Slave stops for engine that only support row-based logging

This is a post-push fix addressing review requests and
problems with extra warnings.

Problem 1: The sub-statement where an unsafe warning was detected was
printed as part of the warning. This was ok for statements that
were unsafe due to, e.g., calls to UUID(), but did not make
sense for statements that were unsafe because there was more than
one autoincrement column (unsafeness in this case comes from the
combination of several sub-statements).
Fix 1: Instead of printing the sub-statement, print an explanation
of why the statement is unsafe.

Problem 2:
When a recursive construct (i.e., stored proceure, stored
function, trigger, view, prepared statement) contained several
sub-statements, and at least one of them was unsafe, there would be
one unsafeness warning per sub-statement - even for safe
sub-statements.
Fix 2:
Ensure that each type of warning is printed at most once, by
remembering throughout the execution of the statement which types
of warnings have been printed.

mysql-test/extra/rpl_tests/create_recursive_construct.inc

@@ -15,12 +15,15 @@
 #  - With SQL_LOG_BIN = 1 and binlog_format = MIXED, to verify that it
 #    writes row events to the binlog.
 #
-#  - If the recursive construct can be invoked so that it has no
-#    side-effects but it returns a value that may be nondeterministic,
-#    then it is invoked in such a way that the return value is
-#    discarded, with SQL_LOG_BIN = 1 and binlog_format = STATEMENT.
-#    In this case, no warning should be given and nothing should be
-#    written to the binlog.
+#  - In some cases, the recursive construct can be invoked so that it
+#    has no side-effects but returns a value that may be
+#    nondeterministic.  An example is a function that returns UUID().
+#    The function does not have side effects but its a return value
+#    that may differ on slave.  Such statements are invoked so that
+#    the return value is discarded (e.g., SELECT func()), with
+#    SQL_LOG_BIN = 1 and binlog_format = STATEMENT.  In this case, no
+#    warning should be given and nothing should be written to the
+#    binlog.
 #
 # This is an auxiliary file particularly targeted to being used by the
 # test binlog_unsafe.  In this context, the purpose is to check how
@@ -289,8 +292,15 @@ if (`SELECT '$CRC_RET_stmt_sidef' != ''`) {
     --eval $CRC_create
   }
 
-  --echo * binlog_format = STATEMENT: expect warning.
+  --echo * binlog_format = STATEMENT: expect $CRC_ARG_expected_number_of_warnings warnings.
   --eval $CRC_RET_stmt_sidef
+  --let $n_warnings= `SHOW COUNT(*) WARNINGS`
+  if (`SELECT '$n_warnings' != '$CRC_ARG_expected_number_of_warnings'`) {
+    --echo Failure! Expected $CRC_ARG_expected_number_of_warnings warnings, got $n_warnings warnings.
+    SHOW WARNINGS;
+    SHOW BINLOG EVENTS;
+    --exit
+  }
 
   # These queries are run without query log, to make result file more
   # readable.  Debug info is only printed if something abnormal
@@ -301,19 +311,33 @@ if (`SELECT '$CRC_RET_stmt_sidef' != ''`) {
   SET SQL_LOG_BIN = 0;
   RESET MASTER;
   --eval $CRC_RET_stmt_sidef
+  --let $n_warnings= `SHOW COUNT(*) WARNINGS`
+  if (`SELECT '$n_warnings' != '0'`) {
+    --echo Failure! Expected 0 warnings, got $n_warnings warnings.
+    SHOW WARNINGS;
+    SHOW BINLOG EVENTS;
+    --exit
+  }
   --let $binlog_event= query_get_value(SHOW BINLOG EVENTS, Event_type, 2)
   if (`SELECT '$binlog_event' != 'No such row'`) {
     --enable_query_log
     --echo Failure! Something was written to the binlog despite SQL_LOG_BIN=0:
     SHOW BINLOG EVENTS;
-    --die
+    --exit
   }
   SET SQL_LOG_BIN = 1;
 
   --echo * binlog_format = MIXED: expect row events in binlog and no warning.
   SET binlog_format = MIXED;
   RESET MASTER;
-  --eval $CRC_RET_stmt_sidef    
+  --eval $CRC_RET_stmt_sidef
+  --let $n_warnings= `SHOW COUNT(*) WARNINGS`
+  if (`SELECT '$n_warnings' != '0'`) {
+    --echo Failure! Expected 0 warnings, got $n_warnings warnings.
+    SHOW WARNINGS;
+    SHOW BINLOG EVENTS;
+    --exit
+  }
   # The first event is format_description, the second is
   # Query_event('BEGIN'), and the third should be our Table_map.
   --let $event_type= query_get_value(SHOW BINLOG EVENTS, Event_type, 3)
@@ -328,7 +352,7 @@ if (`SELECT '$CRC_RET_stmt_sidef' != ''`) {
     # we should instead execute:
     #--enable_query_log
     #SHOW BINLOG EVENTS;
-    #--die
+    #--exit
 
     # Here, we should really source
     # include/show_binlog_events.inc. But due to BUG#41913, that
@@ -352,6 +376,18 @@ if (`SELECT '$CRC_RET_sel_retval' != ''`) {
   --disable_result_log
   --eval $CRC_RET_sel_retval
   --enable_result_log
+
+  # Currently, due to a bug, we do get warnings here, so we don't
+  # fail.  When the bug is fixed, we should execute the following.
+
+  #--let $n_warnings= `SHOW COUNT(*) WARNINGS`
+  #if (`SELECT '$n_warnings' != '0'`) {
+  #  --enable_query_log
+  #  --echo Failure! Expected 0 warnings, got $n_warnings warnings.
+  #  SHOW WARNINGS;
+  #  SHOW BINLOG EVENTS;
+  #  --exit
+  #}
 }
 
 #--echo debug: <<<<EXIT create_recursive_construct