[-Wunused-value] - remove

borrowed/jenny/jenny.c: In function ‘next_builder’:
borrowed/jenny/jenny.c:1164:5: warning: statement with no effect [-Wunused-value]
 1164 |     for (i; i<n-1; ++i) {            /* reset all less significant positions */
      |     ^~~
borrowed/jenny/jenny.c:1172:5: warning: statement with no effect [-Wunused-value]
 1172 |     for (i; i<n-1; ++i) {            /* reset all less significant positions */
      |     ^~~
borrowed/jenny/jenny.c: In function ‘confirm’:
borrowed/jenny/jenny.c:1797:7: warning: statement with no effect [-Wunused-value]
 1797 |       for (i; i<n-1; ++i) {          /* reset all less significant positions */
      |       ^~~
borrowed/jenny/jenny.c:1805:7: warning: statement with no effect [-Wunused-value]
 1805 |       for (i; i<n-1; ++i) {          /* reset all less significant positions */
      |       ^~~

libgnucash/backend/xml/io-gncxml-v2.cpp: In function ‘gboolean qof_session_load_from_xml_file_v2_full(GncXmlBackend*, QofBook*, sixtp_push_handler, gpointer, QofBookFileType)’:
libgnucash/backend/xml/io-gncxml-v2.cpp:806:40: warning: value computed is not used [-Wunused-value]
  806 |                 g_thread_join (thread) != nullptr;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~

libgnucash/engine/Account.cpp: In function ‘void xaccFreeAccount(Account*)’:
libgnucash/engine/Account.cpp:1428:17: warning: statement has no effect [-Wunused-value]
 1428 |     priv->color == nullptr;
      |     ~~~~~~~~~~~~^~~~~~~~~~
libgnucash/engine/Account.cpp:1429:22: warning: statement has no effect [-Wunused-value]
 1429 |     priv->sort_order == nullptr;
      |     ~~~~~~~~~~~~~~~~~^~~~~~~~~~
libgnucash/engine/Account.cpp:1430:17: warning: statement has no effect [-Wunused-value]
 1430 |     priv->notes == nullptr;
      |     ~~~~~~~~~~~~^~~~~~~~~~
libgnucash/engine/Account.cpp:1431:18: warning: statement has no effect [-Wunused-value]
 1431 |     priv->filter == nullptr;
      |     ~~~~~~~~~~~~~^~~~~~~~~~

libgnucash/engine/gnc-int128.cpp: In function ‘void decimal_from_binary(uint64_t*, uint64_t, uint64_t)’:
libgnucash/engine/gnc-int128.cpp:898:36: warning: right operand of comma operator has no effect [-Wunused-value]
  898 |     d[3] = (hi >> 32) & bin_mask, 0;
      |                                    ^

borrowed/jenny/jenny.c

@@ -1161,7 +1161,7 @@ next_builder( state *s, feature *tuple, ub1 n)
     return FALSE;
   else if (tuple[i].f < s->dim[tuple[i].d]-1) {
     ++tuple[i].f;                                       /* increment feature */
-    for (i; i<n-1; ++i) {            /* reset all less significant positions */
+    for (; i<n-1; ++i) {            /* reset all less significant positions */
       tuple[i+1].d = tuple[i].d+1;
       tuple[i+1].f = 0;
     }
@@ -1169,7 +1169,7 @@ next_builder( state *s, feature *tuple, ub1 n)
   else {
     ++tuple[i].d;      /* increment least significant non-maxed-out position */
     tuple[i].f = (ub2)0;                                /* reset its feature */
-    for (i; i<n-1; ++i) {            /* reset all less significant positions */
+    for (; i<n-1; ++i) {            /* reset all less significant positions */
       tuple[i+1].d = tuple[i].d+1;
       tuple[i+1].f = 0;
     }
@@ -1792,7 +1792,7 @@ confirm( state *s)
       break;                                                         /* done */
     else if (offset[i].f < s->dim[offset[i].d]-1) {
       ++offset[i].f;                                    /* increment feature */
-      for (i; i<n-1; ++i) {          /* reset all less significant positions */
+      for (; i<n-1; ++i) {          /* reset all less significant positions */
         offset[i+1].d = offset[i].d+1;
         offset[i+1].f = 0;
       }
@@ -1800,7 +1800,7 @@ confirm( state *s)
     else {
       ++offset[i].d;   /* increment least significant non-maxed-out position */
       offset[i].f = (ub2)0;                             /* reset its feature */
-      for (i; i<n-1; ++i) {          /* reset all less significant positions */
+      for (; i<n-1; ++i) {          /* reset all less significant positions */
         offset[i+1].d = offset[i].d+1;
         offset[i+1].f = 0;
       }

libgnucash/backend/xml/io-gncxml-v2.cpp

@@ -803,7 +803,7 @@ qof_session_load_from_xml_file_v2_full (
                                        generic_callback, gd, book);
             fclose (file);
             if (thread)
-                g_thread_join (thread) != nullptr;
+                g_thread_join (thread);
         }
     }
 

libgnucash/engine/Account.cpp

@@ -1425,10 +1425,10 @@ xaccFreeAccount (Account *acc)
     priv->last_num = nullptr;
     priv->tax_us_code = nullptr;
     priv->tax_us_pns = nullptr;
-    priv->color == nullptr;
-    priv->sort_order == nullptr;
-    priv->notes == nullptr;
-    priv->filter == nullptr;
+    priv->color = nullptr;
+    priv->sort_order = nullptr;
+    priv->notes = nullptr;
+    priv->filter = nullptr;
 
     priv->parent = nullptr;
     priv->children = nullptr;

libgnucash/engine/gnc-int128.cpp

@@ -895,7 +895,7 @@ decimal_from_binary (uint64_t d[dec_array_size], uint64_t hi, uint64_t lo)
     d[0] = lo & bin_mask;
     d[1] = (lo >> 32) & bin_mask;
     d[2] = hi & bin_mask;
-    d[3] = (hi >> 32) & bin_mask, 0;
+    d[3] = (hi >> 32) & bin_mask;
 
     d[0] += coeff_3[3] * d[3] + coeff_2[3] * d[2] + coeff_1[3] * d[1];
     uint64_t q {d[0] / dec_div};