From 0c29f5d69f880b731533a7bc521b41e98f9b64e1 Mon Sep 17 00:00:00 2001
From: Andrew Kesterson <andrew@aklabs.net>
Date: Wed, 6 May 2026 12:36:56 -0400
Subject: [PATCH] Fix handling of CATCH() or FAIL() macros around functions
 that should return an (akerr_ErrorContext *) but return an invalid pointer
 (to something not in our exception array)

---
 CMakeLists.txt               |  3 +++
 src/error.c                  |  6 ++++++
 tests/err_improper_closure.c | 22 ++++++++++++++++++++++
 3 files changed, 31 insertions(+)
 create mode 100644 tests/err_improper_closure.c

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e0d1265..e1e40c8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,9 +36,11 @@ target_compile_definitions(akerror
 add_executable(test_err_catch tests/err_catch.c)
 add_executable(test_err_cleanup tests/err_cleanup.c)
 add_executable(test_err_trace tests/err_trace.c)
+add_executable(test_err_improper_closure tests/err_improper_closure.c)
 add_test(NAME err_catch COMMAND test_err_catch)
 add_test(NAME err_cleanup COMMAND test_err_cleanup)
 add_test(NAME err_trace COMMAND test_err_trace)
+add_test(NAME err_improper_closure COMMAND test_err_improper_closure)
 
 # Specify include directories for the library's headers (if applicable)
 target_include_directories(akerror PUBLIC
@@ -48,6 +50,7 @@ target_include_directories(akerror PUBLIC
 target_link_libraries(test_err_catch PRIVATE akerror)
 target_link_libraries(test_err_cleanup PRIVATE akerror)
 target_link_libraries(test_err_trace PRIVATE akerror)
+target_link_libraries(test_err_improper_closure PRIVATE akerror)
 
 set(main_lib_dest "lib/my_library-${MY_LIBRARY_VERSION}")
 install(TARGETS akerror EXPORT akerror DESTINATION "lib/")
diff --git a/src/error.c b/src/error.c
index f68f10a..0837030 100644
--- a/src/error.c
+++ b/src/error.c
@@ -14,6 +14,12 @@ char __AKERR_ERROR_NAMES[AKERR_MAX_ERR_VALUE+1][AKERR_MAX_ERROR_NAME_LENGTH];
 
 akerr_ErrorContext AKERR_ARRAY_ERROR[AKERR_MAX_ARRAY_ERROR];
 
+int akerr_valid_error_address(akerr_ErrorContext *ptr)
+{
+    // Is this within the memory region occupied by AKERR_ARRAY_ERROR?
+    return ((ptr >= &AKERR_ARRAY_ERROR[0]) && (ptr <= &AKERR_ARRAY_ERROR[AKERR_MAX_ARRAY_ERROR-1]));
+}
+
 void akerr_default_logger(const char *fmt, ...)
 {
 #if defined(AKERR_USE_STDLIB) && AKERR_USE_STDLIB == 1
diff --git a/tests/err_improper_closure.c b/tests/err_improper_closure.c
new file mode 100644
index 0000000..1153736
--- /dev/null
+++ b/tests/err_improper_closure.c
@@ -0,0 +1,22 @@
+#include "akerror.h"
+#include <stdio.h>
+
+akerr_ErrorContext AKERR_NOIGNORE *improper_closure(void)
+{
+    PREPARE_ERROR(errctx);
+    ATTEMPT {
+    } CLEANUP {
+    } PROCESS(errctx) {
+    } FINISH(errctx, true);
+    fprintf(stderr, "Improperly returning from improper_closure\n");
+}
+
+int main(void)
+{
+    PREPARE_ERROR(errctx);
+    ATTEMPT {
+	CATCH(errctx, improper_closure());
+    } CLEANUP {
+    } PROCESS(errctx) {
+    } FINISH_NORETURN(errctx);
+}