Add a new modal for when an exception is encountered in the lib application

src/globals.h

@@ -103,10 +103,18 @@ typedef struct swap_app_context_s {
 extern swap_app_context_t G_swap_ctx;
 
 #ifdef HAVE_NBGL
+
+// Boolean like status + a special value
+typedef enum last_cycle_status_e {
+    LAST_CYCLE_ERROR = 0,
+    LAST_CYCLE_SUCCESS = 1,
+    LAST_CYCLE_EXCEPTION = 2,
+} last_cycle_status_t;
+
 // On Stax, remember some data from the previous cycle if applicable to display a status screen
 typedef struct previous_cycle_data_s {
     bool had_previous_cycle;
-    bool was_successful;
+    last_cycle_status_t was_successful;
     char appname_last_cycle[BOLOS_APPNAME_MAX_SIZE_B + 1];
 } previous_cycle_data_t;
 

src/main.c

@@ -135,12 +135,16 @@ __attribute__((section(".boot"))) int main(__attribute__((unused)) int arg0) {
                 //  - we need a BSS reset + UX_INIT
                 if (G_previous_cycle_data.had_previous_cycle) {
                     G_previous_cycle_data.had_previous_cycle = false;
-                    if (G_previous_cycle_data.was_successful) {
+                    if (G_previous_cycle_data.was_successful == LAST_CYCLE_ERROR) {
+                        PRINTF("Displaying modal for failed last cycle\n");
+                        display_signing_failure(G_previous_cycle_data.appname_last_cycle);
+                    } else if (G_previous_cycle_data.was_successful == LAST_CYCLE_SUCCESS) {
                         PRINTF("Displaying modal for successful last cycle\n");
                         display_signing_success();
                     } else {
-                        PRINTF("Displaying modal for failed last cycle\n");
-                        display_signing_failure(G_previous_cycle_data.appname_last_cycle);
+                        // LAST_CYCLE_EXCEPTION
+                        PRINTF("Displaying modal for exception last cycle\n");
+                        display_signing_exception(G_previous_cycle_data.appname_last_cycle);
                     }
                 } else {
                     ui_idle();

src/ui/sign_result.c

@@ -12,6 +12,13 @@
      (sizeof(REFUSAL_TEXT_PART_2) - 1) + 1)
 static char refusal_text[REFUSAL_TEXT_MAX_SIZE];
 
+#define EXCEPTION_TEXT_PART_1 "Exception raised\nby the\n"
+#define EXCEPTION_TEXT_PART_2 " app.\nTransaction state is unknown"
+#define EXCEPTION_TEXT_MAX_SIZE                                                         \
+    ((sizeof(EXCEPTION_TEXT_PART_1) - 1) + (sizeof(G_swap_ctx.payin_binary_name) - 1) + \
+     (sizeof(EXCEPTION_TEXT_PART_2) - 1) + 1)
+static char exception_text[EXCEPTION_TEXT_MAX_SIZE];
+
 void display_signing_failure(const char *appname) {
     snprintf(refusal_text,
              sizeof(refusal_text),
@@ -26,4 +33,14 @@ void display_signing_success(void) {
     nbgl_useCaseReviewStatus(STATUS_TYPE_TRANSACTION_SIGNED, ui_idle);
 }
 
+void display_signing_exception(const char *appname) {
+    snprintf(exception_text,
+             sizeof(exception_text),
+             "%s%s%s",
+             REFUSAL_TEXT_PART_1,
+             appname,
+             REFUSAL_TEXT_PART_2);
+    nbgl_useCaseStatus(exception_text, false, ui_idle);
+}
+
 #endif  // HAVE_NBGL

src/ui/sign_result.h

@@ -7,4 +7,5 @@
 // The "Ledger Moment" modal is only available on Stax
 void display_signing_success(void);
 void display_signing_failure(const char *appname);
+void display_signing_exception(const char *appname);
 #endif  // HAVE_NBGL