use GNUNET_NZL instead of crazy hacks to ensure non-zero vararg array lengths

2 files changed, 185 insertions, 198 deletions

diff --git a/src/backenddb/plugin_merchantdb_postgres.c b/src/backenddb/plugin_merchantdb_postgres.c
index b6277183..c7427d77 100644
--- a/src/backenddb/plugin_merchantdb_postgres.c
+++ b/src/backenddb/plugin_merchantdb_postgres.c
@@ -2506,218 +2506,207 @@ process_deposits_for_refund_cb (void *cls,
 				unsigned int num_results)
 {
   struct InsertRefundContext *ctx = cls;
+  struct TALER_Amount current_refund;
+  struct TALER_Amount deposit_refund[GNUNET_NZL(num_results)];
+  struct TALER_CoinSpendPublicKeyP deposit_coin_pubs[GNUNET_NZL(num_results)];
+  struct TALER_Amount deposit_amount_with_fee[GNUNET_NZL(num_results)];
+  struct TALER_Amount deposit_refund_fee[GNUNET_NZL(num_results)];
 
-  if (0 == num_results)
-  {
-    ctx->qs = GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
-    /* We must return early here, or the zero-length variable size arrays below
-       will be undefined behavior */
-    return;
-  }
+  GNUNET_assert (GNUNET_OK ==
+                 TALER_amount_get_zero (ctx->refund->currency,
+                                        &current_refund));
 
+  /* Pass 1:  Collect amount of existing refunds into current_refund.
+   * Also store existing refunded amount for each deposit in deposit_refund. */
+
+  for (unsigned int i=0; i<num_results; i++)
   {
-    struct TALER_Amount current_refund;
-    struct TALER_Amount deposit_refund[num_results];
-    struct TALER_CoinSpendPublicKeyP deposit_coin_pubs[num_results];
-    struct TALER_Amount deposit_amount_with_fee[num_results];
-    struct TALER_Amount deposit_refund_fee[num_results];
+    struct TALER_CoinSpendPublicKeyP coin_pub;
+    struct TALER_Amount amount_with_fee;
+    struct TALER_Amount refund_fee;
+    struct GNUNET_PQ_ResultSpec rs[] = {
+      GNUNET_PQ_result_spec_auto_from_type ("coin_pub",
+                                            &coin_pub),
+      TALER_PQ_result_spec_amount ("amount_with_fee",
+                                   &amount_with_fee),
+      TALER_PQ_result_spec_amount ("refund_fee",
+                                   &refund_fee),
+      GNUNET_PQ_result_spec_end
+    };
 
-    GNUNET_assert (GNUNET_OK ==
-                   TALER_amount_get_zero (ctx->refund->currency,
-                                          &current_refund));
+    if (GNUNET_OK !=
+        GNUNET_PQ_extract_result (result,
+                                  rs,
+                                  i))
+    {
+      GNUNET_break (0);
+      ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
+      return;
+    }
 
-    /* Pass 1:  Collect amount of existing refunds into current_refund.
-     * Also store existing refunded amount for each deposit in deposit_refund. */
+    struct FindRefundContext ictx;
+    enum GNUNET_DB_QueryStatus ires;
+    struct GNUNET_PQ_QueryParam params[] = {
+      GNUNET_PQ_query_param_auto_from_type (&coin_pub),
+      GNUNET_PQ_query_param_end
+    };
 
-    for (unsigned int i=0; i<num_results; i++)
+    GNUNET_assert (GNUNET_OK ==
+                   TALER_amount_get_zero (ctx->refund->currency,
+                                          &ictx.refunded_amount));
+    ictx.err = GNUNET_OK; /* no error so far */
+    ires = GNUNET_PQ_eval_prepared_multi_select (ctx->pg->conn,
+                                                 "find_refunds",
+                                                 params,
+                                                 &process_refund_cb,
+                                                 &ictx);
+    if ( (GNUNET_OK != ictx.err) ||
+         (GNUNET_DB_STATUS_HARD_ERROR == ires) )
     {
-      struct TALER_CoinSpendPublicKeyP coin_pub;
-      struct TALER_Amount amount_with_fee;
-      struct TALER_Amount refund_fee;
-      struct GNUNET_PQ_ResultSpec rs[] = {
-        GNUNET_PQ_result_spec_auto_from_type ("coin_pub",
-                                              &coin_pub),
-        TALER_PQ_result_spec_amount ("amount_with_fee",
-                                     &amount_with_fee),
-        TALER_PQ_result_spec_amount ("refund_fee",
-                                     &refund_fee),
-        GNUNET_PQ_result_spec_end
-      };
+      GNUNET_break (0);
+      ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
+      return;
+    }
+    if (GNUNET_DB_STATUS_SOFT_ERROR == ires)
+    {
+      ctx->qs = GNUNET_DB_STATUS_SOFT_ERROR;
+      return;
+    }
+    deposit_refund[i] = ictx.refunded_amount;
+    deposit_amount_with_fee[i] = amount_with_fee;
+    deposit_coin_pubs[i] = coin_pub;
+    deposit_refund_fee[i] = refund_fee;
+    if (GNUNET_SYSERR ==
+	TALER_amount_add (&current_refund,
+			  &current_refund,
+			  &ictx.refunded_amount))
+    {
+      GNUNET_break (0);
+      ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
+      return;
+    }
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Existing refund for coin %s is %s\n",
+                TALER_B2S (&coin_pub),
+                TALER_amount2s (&ictx.refunded_amount));
+  }
 
-      if (GNUNET_OK !=
-          GNUNET_PQ_extract_result (result,
-                                    rs,
-                                    i))
-      {
-        GNUNET_break (0);
-        ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
-        return;
-      }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Total existing refund is %s\n",
+              TALER_amount2s (&current_refund));
 
-      struct FindRefundContext ictx;
-      enum GNUNET_DB_QueryStatus ires;
-      struct GNUNET_PQ_QueryParam params[] = {
-        GNUNET_PQ_query_param_auto_from_type (&coin_pub),
-        GNUNET_PQ_query_param_end
-      };
+  /* stop immediately if we are done */
+  if (0 >= TALER_amount_cmp (ctx->refund,
+                             &current_refund))
+  {
+    ctx->qs = GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
+    return;
+  }
 
-      GNUNET_assert (GNUNET_OK ==
-                     TALER_amount_get_zero (ctx->refund->currency,
-                                            &ictx.refunded_amount));
-      ictx.err = GNUNET_OK; /* no error so far */
-      ires = GNUNET_PQ_eval_prepared_multi_select (ctx->pg->conn,
-                                                   "find_refunds",
-                                                   params,
-                                                   &process_refund_cb,
-                                                   &ictx);
-      if ( (GNUNET_OK != ictx.err) ||
-           (GNUNET_DB_STATUS_HARD_ERROR == ires) )
-      {
-        GNUNET_break (0);
-        ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
-        return;
-      }
-      if (GNUNET_DB_STATUS_SOFT_ERROR == ires)
-      {
-        ctx->qs = GNUNET_DB_STATUS_SOFT_ERROR;
-        return;
-      }
-      deposit_refund[i] = ictx.refunded_amount;
-      deposit_amount_with_fee[i] = amount_with_fee;
-      deposit_coin_pubs[i] = coin_pub;
-      deposit_refund_fee[i] = refund_fee;
-      if (GNUNET_SYSERR ==
-          TALER_amount_add (&current_refund,
-                            &current_refund,
-                            &ictx.refunded_amount))
-      {
-        GNUNET_break (0);
-        ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
-        return;
-      }
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "Existing refund for coin %s is %s\n",
-                  TALER_B2S (&coin_pub),
-                  TALER_amount2s (&ictx.refunded_amount));
-    }
+  /* Phase 2:  Try to increase current refund until it matches desired refund */
 
-    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                "Total existing refund is %s\n",
-                TALER_amount2s (&current_refund));
+  for (unsigned int i=0;i<num_results; i++)
+  {
+    const struct TALER_Amount *increment;
+    struct TALER_Amount left;
+    struct TALER_Amount remaining_refund;
 
-    /* stop immediately if we are done */
-    if (0 >= TALER_amount_cmp (ctx->refund,
-                               &current_refund))
+    /* How much of the coin is left after the existing refunds? */
+    if (GNUNET_SYSERR ==
+	TALER_amount_subtract (&left,
+			       &deposit_amount_with_fee[i],
+			       &deposit_refund[i]))
     {
-      ctx->qs = GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
+      GNUNET_break (0);
+      ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
       return;
     }
 
-    /* Phase 2:  Try to increase current refund until it matches desired refund */
-
-    for (unsigned int i=0;i<num_results; i++)
+    if ( (0 == left.value) &&
+	 (0 == left.fraction) )
     {
-      const struct TALER_Amount *increment;
-      struct TALER_Amount left;
-      struct TALER_Amount remaining_refund;
-
-      /* How much of the coin is left after the existing refunds? */
-      if (GNUNET_SYSERR ==
-          TALER_amount_subtract (&left,
-                                 &deposit_amount_with_fee[i],
-                                 &deposit_refund[i]))
-      {
-        GNUNET_break (0);
-        ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
-        return;
-      }
-
-      if ( (0 == left.value) &&
-           (0 == left.fraction) )
-      {
-        /* coin was fully refunded, move to next coin */
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    "Coin %s fully refunded, moving to next coin\n",
-                    TALER_B2S (&deposit_coin_pubs[i]));
-        continue;
-      }
+      /* coin was fully refunded, move to next coin */
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+		  "Coin %s fully refunded, moving to next coin\n",
+		  TALER_B2S (&deposit_coin_pubs[i]));
+      continue;
+    }
 
-      /* How much of the refund is left? */
-      if (GNUNET_SYSERR ==
-          TALER_amount_subtract (&remaining_refund,
-                                 ctx->refund,
-                                 &current_refund))
-      {
-        GNUNET_break (0);
-        ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
-        return;
-      }
+    /* How much of the refund is left? */
+    if (GNUNET_SYSERR ==
+	TALER_amount_subtract (&remaining_refund,
+			       ctx->refund,
+			       &current_refund))
+    {
+      GNUNET_break (0);
+      ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
+      return;
+    }
 
-      /* By how much will we increase the refund for this coin? */
-      if (0 >= TALER_amount_cmp (&remaining_refund,
-                                 &left))
-      {
-        /* remaining_refund <= left */
-        increment = &remaining_refund;
-      }
-      else
-      {
-        increment = &left;
-      }
+    /* By how much will we increase the refund for this coin? */
+    if (0 >= TALER_amount_cmp (&remaining_refund,
+			       &left))
+    {
+      /* remaining_refund <= left */
+      increment = &remaining_refund;
+    }
+    else
+    {
+      increment = &left;
+    }
 
-      if (GNUNET_SYSERR ==
-          TALER_amount_add (&current_refund,
-                            &current_refund,
-                            increment))
-      {
-        GNUNET_break (0);
-        ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
-        return;
-      }
+    if (GNUNET_SYSERR ==
+	TALER_amount_add (&current_refund,
+			  &current_refund,
+			  increment))
+    {
+      GNUNET_break (0);
+      ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
+      return;
+    }
 
-      /* actually run the refund */
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "Coin %s deposit amount is %s\n",
-                  TALER_B2S (&deposit_coin_pubs[i]),
-                  TALER_amount2s (&deposit_amount_with_fee[i]));
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "Coin %s refund will be incremented by %s\n",
-                  TALER_B2S (&deposit_coin_pubs[i]),
-                  TALER_amount2s (increment));
+    /* actually run the refund */
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+		"Coin %s deposit amount is %s\n",
+		TALER_B2S (&deposit_coin_pubs[i]),
+		TALER_amount2s (&deposit_amount_with_fee[i]));
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+		"Coin %s refund will be incremented by %s\n",
+		TALER_B2S (&deposit_coin_pubs[i]),
+		TALER_amount2s (increment));
+    {
+      enum GNUNET_DB_QueryStatus qs;
+
+      if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT !=
+	  (qs = insert_refund (ctx->pg,
+			       ctx->merchant_pub,
+			       ctx->h_contract_terms,
+			       &deposit_coin_pubs[i],
+			       ctx->reason,
+			       increment,
+			       &deposit_refund_fee[i])))
       {
-        enum GNUNET_DB_QueryStatus qs;
-
-        if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT !=
-            (qs = insert_refund (ctx->pg,
-                                 ctx->merchant_pub,
-                                 ctx->h_contract_terms,
-                                 &deposit_coin_pubs[i],
-                                 ctx->reason,
-                                 increment,
-                                 &deposit_refund_fee[i])))
-        {
-          GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
-          ctx->qs = qs;
-          return;
-        }
+	GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+	ctx->qs = qs;
+	return;
       }
-      /* stop immediately if we are done */
-      if (0 == TALER_amount_cmp (ctx->refund,
-                                 &current_refund))
-        return;
     }
-
-    /**
-     * We end up here if nto all of the refund has been covered.
-     * Although this should be checked as the business should never
-     * issue a refund bigger than the contract's actual price, we cannot
-     * rely upon the frontend being correct.
-     */
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "The refund of %s is bigger than the order's value\n",
-                TALER_amount2s (ctx->refund));
-    ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
+    /* stop immediately if we are done */
+    if (0 == TALER_amount_cmp (ctx->refund,
+                               &current_refund))
+      return;
   }
+
+  /**
+   * We end up here if nto all of the refund has been covered.
+   * Although this should be checked as the business should never
+   * issue a refund bigger than the contract's actual price, we cannot
+   * rely upon the frontend being correct.
+   */
+  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+	      "The refund of %s is bigger than the order's value\n",
+	      TALER_amount2s (ctx->refund));
+  ctx->qs = GNUNET_DB_STATUS_HARD_ERROR;
 }
 
 
diff --git a/src/lib/merchant_api_pay.c b/src/lib/merchant_api_pay.c
index b0a2f0e0..973a9b5e 100644
--- a/src/lib/merchant_api_pay.c
+++ b/src/lib/merchant_api_pay.c
@@ -76,7 +76,7 @@ struct TALER_MERCHANT_Pay
    * Operational mode, either "pay" or "abort-refund".
    */
   const char *mode;
-  
+
   /**
    * Reference to the execution context.
    */
@@ -96,7 +96,7 @@ struct TALER_MERCHANT_Pay
    * Hash of the contract, only available in "abort-refund" mode.
    */
   struct GNUNET_HashCode h_contract_terms;
-  
+
 };
 
 
@@ -132,9 +132,7 @@ check_abort_refund (struct TALER_MERCHANT_Pay *ph,
   }
   num_refunds = json_array_size (refunds);
   {
-    /* The "+ 1" is necessary since num_refunds might be 0, and variable size arrays must
-     * be >0, or it's undefined behavior */
-    struct TALER_MERCHANT_RefundEntry res[num_refunds + 1];
+    struct TALER_MERCHANT_RefundEntry res[GNUNET_NZL(num_refunds)];
 
     for (unsigned int i=0;i<num_refunds;i++)
     {
@@ -166,7 +164,7 @@ check_abort_refund (struct TALER_MERCHANT_Pay *ph,
       rr.purpose.size = htonl (sizeof (struct TALER_RefundRequestPS));
       rr.h_contract_terms = ph->h_contract_terms;
       rr.coin_pub = res[i].coin_pub;
-      rr.merchant = merchant_pub;      
+      rr.merchant = merchant_pub;
       rr.rtransaction_id = GNUNET_htonll (res[i].rtransaction_id);
       found = -1;
       for (unsigned int j=0;j<ph->num_coins;j++)
@@ -373,7 +371,7 @@ handle_pay_finished (void *cls,
       GNUNET_break (0);
       response_code = 0;
       break;
-    }    
+    }
     ph->pay_cb (ph->pay_cb_cls,
 		response_code,
 		TALER_JSON_get_error_code (json),
@@ -383,7 +381,7 @@ handle_pay_finished (void *cls,
   {
     GNUNET_assert (0 == strcasecmp (ph->mode,
 				    "abort-refund"));
-    
+
     switch (response_code)
     {
     case 0:
@@ -425,7 +423,7 @@ handle_pay_finished (void *cls,
       GNUNET_break (0);
       response_code = 0;
       break;
-    }    
+    }
     ph->abort_cb (ph->abort_cb_cls,
 		  response_code,
 		  TALER_JSON_get_error_code (json),
@@ -435,7 +433,7 @@ handle_pay_finished (void *cls,
 		  NULL,
 		  json);
   }
-    
+
   TALER_MERCHANT_pay_cancel (ph);
 }
 
@@ -660,7 +658,7 @@ prepare_pay_generic (struct GNUNET_CURL_Context *ctx,
     GNUNET_break (0);
     return NULL;
   }
-  
+
   dr.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_DEPOSIT);
   dr.purpose.size = htonl (sizeof (struct TALER_DepositRequestPS));
   dr.h_contract_terms = *h_contract_terms;