fix the maintain of oneof_field in type.

.github/workflows/test.yml

@@ -27,7 +27,7 @@ jobs:
     steps:
       - name: Install LCov
         run: |
-          sudo apt install libperlio-gzip-perl libjson-perl
+          sudo apt install libperlio-gzip-perl libjson-perl libcapture-tiny-perl
           wget "https://github.com/linux-test-project/lcov/archive/master.zip"
           unzip "master.zip"
           cd "lcov-master"

.gitignore

@@ -15,6 +15,8 @@
 *.pdb
 *.rock
 *.so
+*.o
+*.gc*
 google
 lua*/
 out*

pb.c

@@ -1169,8 +1169,10 @@ typedef enum {USE_FIELD = 1, USE_REPEAT = 2, USE_MESSAGE = 4} lpb_DefFlags;
 
 static void lpb_pushtypetable(lua_State *L, lpb_State *LS, const pb_Type *t);
 
-static void lpb_newmsgtable(lua_State *L, const pb_Type *t)
-{ lua_createtable(L, 0, t->field_count - t->oneof_field + t->oneof_count*2); }
+static void lpb_newmsgtable(lua_State *L, const pb_Type *t) {
+    int fieldcnt = t->field_count - t->oneof_field + t->oneof_count*2;
+    lua_createtable(L, 0, fieldcnt > 0 ? fieldcnt : 0);
+}
 
 LUALIB_API const pb_Type *lpb_type(lpb_State *LS, pb_Slice s) {
     const pb_Type *t;

pb.h

@@ -1323,7 +1323,10 @@ PB_API void pb_delfield(pb_State *S, pb_Type *t, pb_Field *f) {
     tf = (pb_FieldEntry*)pb_gettable(&t->field_tags, (pb_Key)f->number);
     if (nf && nf->value == f) nf->entry.key = 0, nf->value = NULL, ++count;
     if (tf && tf->value == f) tf->entry.key = 0, tf->value = NULL, ++count;
-    if (count) pbT_freefield(S, f), --t->field_count;
+    if (count) {
+        if (f->oneof_idx) --t->oneof_field; 
+        pbT_freefield(S, f), --t->field_count;
+    }
     pb_delsort(t);
 }