[Payments] Handle absence of total in modifier.

Before this patch, a modifier without a total field would crash on
desktop.

This patch adds a check for presence of the total field in the modifier
before dereferencing it. If the modifier total is absent, then the
global total is used.

After this patch, a modifier without a total field results in the global
total being used without a crash.

Bug: 814968
Change-Id: I1f946ed4526b948b2836e2144e3bdb2e7c167321
Reviewed-on: https://chromium-review.googlesource.com/935426Reviewed-by: anthonyvd <anthonyvd@chromium.org>
Commit-Queue: Rouslan Solomakhin <rouslan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539176}

chrome/browser/ui/views/payments/modifiers_browsertest.cc

@@ -288,4 +288,40 @@ IN_PROC_BROWSER_TEST_F(PaymentRequestModifiersTest,
                    ->child_count());
 }
 
+IN_PROC_BROWSER_TEST_F(PaymentRequestModifiersTest,
+                       NoTotalInModifierDoesNotCrash) {
+  NavigateTo("/payment_request_bobpay_and_basic_card_with_modifiers_test.html");
+  autofill::AutofillProfile profile(autofill::test::GetFullProfile());
+  AddAutofillProfile(profile);
+  autofill::CreditCard card(autofill::test::GetCreditCard());  // Visa card.
+  // Change to Mastercard to match the test case.
+  card.SetRawInfo(autofill::CREDIT_CARD_NUMBER,
+                  base::ASCIIToUTF16("5555555555554444"));
+  card.set_billing_address_id(profile.guid());
+  AddCreditCard(card);
+
+  ResetEventWaiter(DialogEvent::DIALOG_OPENED);
+  content::WebContents* web_contents = GetActiveWebContents();
+  const std::string click_buy_button_js =
+      "(function() { document.getElementById('no_total').click(); })();";
+  ASSERT_TRUE(content::ExecuteScript(web_contents, click_buy_button_js));
+  WaitForObservedEvent();
+  // The web-modal dialog should be open.
+  web_modal::WebContentsModalDialogManager* web_contents_modal_dialog_manager =
+      web_modal::WebContentsModalDialogManager::FromWebContents(web_contents);
+  EXPECT_TRUE(web_contents_modal_dialog_manager->IsDialogActive());
+
+  OpenOrderSummaryScreen();
+
+  // The price is the global total, because the modifier does not have total.
+  EXPECT_EQ(base::ASCIIToUTF16("$5.00"),
+            GetLabelText(DialogViewID::ORDER_SUMMARY_TOTAL_AMOUNT_LABEL));
+  // Only global total is available.
+  EXPECT_EQ(1, dialog_view()
+                   ->view_stack_for_testing()
+                   ->top()
+                   ->GetViewByID(static_cast<int>(DialogViewID::CONTENT_VIEW))
+                   ->child_count());
+}
+
 }  // namespace payments

components/payments/content/payment_request_spec.cc

@@ -189,7 +189,7 @@ const mojom::PaymentItemPtr& PaymentRequestSpec::GetTotal(
     PaymentInstrument* selected_instrument) const {
   const mojom::PaymentDetailsModifierPtr* modifier =
       GetApplicableModifier(selected_instrument);
-  return modifier ? (*modifier)->total : details_->total;
+  return modifier && (*modifier)->total ? (*modifier)->total : details_->total;
 }
 
 std::vector<const mojom::PaymentItemPtr*> PaymentRequestSpec::GetDisplayItems(

components/test/data/payments/bobpay_and_basic_card_with_modifiers.js

@@ -53,8 +53,7 @@ function buy() {  // eslint-disable-line no-unused-vars
 function buyWithBobPayDiscount() {  // eslint-disable-line no-unused-vars
   try {
     new PaymentRequest(
-        [{supportedMethods: ['https://bobpay.com', 'basic-card']}],
-        {
+        [{supportedMethods: ['https://bobpay.com', 'basic-card']}], {
           total: {label: 'Total', amount: {currency: 'USD', value: '5.00'}},
           modifiers: [{
             supportedMethods: ['https://bobpay.com'],
@@ -72,13 +71,13 @@ function buyWithBobPayDiscount() {  // eslint-disable-line no-unused-vars
         .show()
         .then(function(resp) {
           resp.complete('success')
-            .then(function() {
-              print(JSON.stringify(resp, undefined, 2));
-            })
-            .catch(function(error) {
-              print(error.message);
-            });
-          })
+              .then(function() {
+                print(JSON.stringify(resp, undefined, 2));
+              })
+              .catch(function(error) {
+                print(error.message);
+              });
+        })
         .catch(function(error) {
           print(error.message);
         });
@@ -137,40 +136,40 @@ function creditSupportedType() {  // eslint-disable-line no-unused-vars
 function debitSupportedType() {  // eslint-disable-line no-unused-vars
   try {
     new PaymentRequest(
-      [{supportedMethods: ['https://bobpay.com', 'basic-card']}], {
-        total: {label: 'Total', amount: {currency: 'USD', value: '5.00'}},
-        modifiers: [{
-          supportedMethods: ['basic-card'],
-          total: {
-            label: 'Total',
-            amount: {currency: 'USD', value: '4.00'},
-          },
-          additionalDisplayItems: [{
-            label: 'basic-card discount',
-            amount: {currency: 'USD', value: '-1.00'},
+        [{supportedMethods: ['https://bobpay.com', 'basic-card']}], {
+          total: {label: 'Total', amount: {currency: 'USD', value: '5.00'}},
+          modifiers: [{
+            supportedMethods: ['basic-card'],
+            total: {
+              label: 'Total',
+              amount: {currency: 'USD', value: '4.00'},
+            },
+            additionalDisplayItems: [{
+              label: 'basic-card discount',
+              amount: {currency: 'USD', value: '-1.00'},
+            }],
+            data: {
+              discountProgramParticipantId: '86328764873265',
+              supportedTypes: ['debit'],
+            },
           }],
-          data: {
-            discountProgramParticipantId: '86328764873265',
-            supportedTypes: ['debit'],
-          },
-        }],
-      })
-      .show()
-      .then(function(resp) {
-        resp.complete('success')
-        .then(function() {
-          print(JSON.stringify(resp, undefined, 2));
+        })
+        .show()
+        .then(function(resp) {
+          resp.complete('success')
+              .then(function() {
+                print(JSON.stringify(resp, undefined, 2));
+              })
+              .catch(function(error) {
+                print(error.message);
+              });
         })
         .catch(function(error) {
           print(error.message);
         });
-      })
-      .catch(function(error) {
-        print(error.message);
-      });
-    } catch (error) {
-      print(error.message);
-    }
+  } catch (error) {
+    print(error.message);
+  }
 }
 
 /**
@@ -266,7 +265,7 @@ function mastercardSupportedNetwork() {  // eslint-disable-line no-unused-vars
  * Launches the PaymentRequest UI with Bob Pay and basic-card as payment
  * methods and a modifier for basic-card with "mastercard" network.
  */
-function mastercardAnySupportedType() { // eslint-disable-line no-unused-vars
+function mastercardAnySupportedType() {  // eslint-disable-line no-unused-vars
   try {
     new PaymentRequest(
         [{supportedMethods: ['https://bobpay.com', 'basic-card']}], {
@@ -304,3 +303,40 @@ function mastercardAnySupportedType() { // eslint-disable-line no-unused-vars
     print(error.message);
   }
 }
+
+/**
+ * Launches the PaymentRequest UI with basic-card as payment method and a
+ * modifier for basic-card with "mastercard" network, but the modifier does not
+ * have a total specified.
+ */
+function noTotal() {  // eslint-disable-line no-unused-vars
+  try {
+    new PaymentRequest([{supportedMethods: 'basic-card'}], {
+      total: {label: 'Total', amount: {currency: 'USD', value: '5.00'}},
+      modifiers: [
+        {
+          supportedMethods: ['basic-card'],
+          data: {
+            mastercardProgramParticipantId: '86328764873265',
+            supportedNetworks: ['mastercard'],
+          },
+        },
+      ],
+    })
+        .show()
+        .then(function(resp) {
+          resp.complete('success')
+              .then(function() {
+                print(JSON.stringify(resp, undefined, 2));
+              })
+              .catch(function(error) {
+                print(error.message);
+              });
+        })
+        .catch(function(error) {
+          print(error.message);
+        });
+  } catch (error) {
+    print(error.message);
+  }
+}

components/test/data/payments/payment_request_bobpay_and_basic_card_with_modifiers_test.html

@@ -19,6 +19,7 @@ found in the LICENSE file.
 <button onclick="visaSupportedNetwork()" id="visa_supported_network">Bob Pay and Basic-Card with Basic-Card modifiers Test with visa supported network and credit supported type</button>
 <button onclick="mastercardSupportedNetwork()" id="mastercard_supported_network">Bob Pay and Basic-Card with Basic-Card modifiers Test with mastercard supported network and credit supported type</button>
 <button onclick="mastercardAnySupportedType()" id="mastercard_any_supported_type">Bob Pay and Basic-Card with Basic-Card modifiers Test with mastercard supported network and any supported type</button>
+<button onclick="noTotal()" id="no_total">No Total</button>
 <pre id="result"></pre>
 <script src="util.js"></script>
 <script src="bobpay_and_basic_card_with_modifiers.js"></script>