Fix emitter states handling when write_indicator fails

There are cases where yaml_emitter_write_indicator fails.
In that case POP is called on emitter->indents but not on emitter->states,
which results in a leftover event in the stack, and later POP is called
on an empty emitter->indents stack.

This commit does not fix the case of the failing yaml_emitter_write_indicator.
This is still investigated.

src/emitter.c

@@ -759,6 +759,7 @@ yaml_emitter_emit_flow_sequence_item(yaml_emitter_t *emitter,
     {
         emitter->flow_level --;
         emitter->indent = POP(emitter, emitter->indents);
+        emitter->state = POP(emitter, emitter->states);
         if (emitter->canonical && !first) {
             if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
                 return 0;
@@ -767,7 +768,6 @@ yaml_emitter_emit_flow_sequence_item(yaml_emitter_t *emitter,
         }
         if (!yaml_emitter_write_indicator(emitter, "]", 0, 0, 0))
             return 0;
-        emitter->state = POP(emitter, emitter->states);
 
         return 1;
     }
@@ -808,6 +808,7 @@ yaml_emitter_emit_flow_mapping_key(yaml_emitter_t *emitter,
     {
         emitter->flow_level --;
         emitter->indent = POP(emitter, emitter->indents);
+        emitter->state = POP(emitter, emitter->states);
         if (emitter->canonical && !first) {
             if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
                 return 0;
@@ -816,7 +817,6 @@ yaml_emitter_emit_flow_mapping_key(yaml_emitter_t *emitter,
         }
         if (!yaml_emitter_write_indicator(emitter, "}", 0, 0, 0))
             return 0;
-        emitter->state = POP(emitter, emitter->states);
 
         return 1;
     }