Suggested changes from Tim

Remove leading _, change the trace string building to append the comma
within the loop

Author: NattyNarwhal

Zend/zend_exceptions.c

@@ -506,7 +506,7 @@ ZEND_METHOD(ErrorException, getSeverity)
 		} \
 	} while (0)
 
-static void _build_trace_args(zval *arg, smart_str *str) /* {{{ */
+static void build_trace_args(zval *arg, smart_str *str) /* {{{ */
 {
 	/* the trivial way would be to do
 	 * convert_to_string(arg);
@@ -516,24 +516,21 @@ static void _build_trace_args(zval *arg, smart_str *str) /* {{{ */
 
 	ZVAL_DEREF(arg);
 
-	if (smart_str_append_zval(str, arg, EG(exception_string_param_max_len)) == SUCCESS) {
-		smart_str_appends(str, ", ");
-	} else {
+	if (smart_str_append_zval(str, arg, EG(exception_string_param_max_len)) != SUCCESS) {
 		switch (Z_TYPE_P(arg)) {
 			case IS_RESOURCE:
 				smart_str_appends(str, "Resource id #");
 				smart_str_append_long(str, Z_RES_HANDLE_P(arg));
-				smart_str_appends(str, ", ");
 				break;
 			case IS_ARRAY:
-				smart_str_appends(str, "Array, ");
+				smart_str_appends(str, "Array");
 				break;
 			case IS_OBJECT: {
 				zend_string *class_name = Z_OBJ_HANDLER_P(arg, get_class_name)(Z_OBJ_P(arg));
 				smart_str_appends(str, "Object(");
 				/* cut off on NULL byte ... class@anonymous */
 				smart_str_appends(str, ZSTR_VAL(class_name));
-				smart_str_appends(str, "), ");
+				smart_str_appends(str, ")");
 				zend_string_release_ex(class_name, 0);
 				break;
 			}
@@ -542,32 +539,32 @@ static void _build_trace_args(zval *arg, smart_str *str) /* {{{ */
 }
 /* }}} */
 
-static void _build_trace_args_list(zval *tmp, smart_str *str) /* {{{ */
+static void build_trace_args_list(zval *tmp, smart_str *str) /* {{{ */
 {
 	if (EXPECTED(Z_TYPE_P(tmp) == IS_ARRAY)) {
-		size_t last_len = ZSTR_LEN(str->s);
 		zend_string *name;
 		zval *arg;
+		HashTable *ht = Z_ARRVAL_P(tmp);
+		uint32_t index = 0;
 
-		ZEND_HASH_FOREACH_STR_KEY_VAL(Z_ARRVAL_P(tmp), name, arg) {
+		ZEND_HASH_FOREACH_STR_KEY_VAL(ht, name, arg) {
 			if (name) {
 				smart_str_append(str, name);
 				smart_str_appends(str, ": ");
 			}
-			_build_trace_args(arg, str);
+			build_trace_args(arg, str);
+			if (++index != zend_hash_num_elements(ht)) {
+				smart_str_appends(str, ", ");
+			}
 		} ZEND_HASH_FOREACH_END();
-
-		if (last_len != ZSTR_LEN(str->s)) {
-			ZSTR_LEN(str->s) -= 2; /* remove last ', ' */
-		}
 	} else {
 		/* only happens w/ reflection abuse (Zend/tests/bug63762.phpt) */
 		zend_error(E_WARNING, "args element is not an array");
 	}
 }
 /* }}} */
 
-static void _build_trace_string(smart_str *str, const HashTable *ht, uint32_t num) /* {{{ */
+static void build_trace_string(smart_str *str, const HashTable *ht, uint32_t num) /* {{{ */
 {
 	zval *file, *tmp;
 
@@ -613,7 +610,7 @@ static void _build_trace_string(smart_str *str, const HashTable *ht, uint32_t nu
 	smart_str_appendc(str, '(');
 	tmp = zend_hash_find_known_hash(ht, ZSTR_KNOWN(ZEND_STR_ARGS));
 	if (tmp) {
-		_build_trace_args_list(tmp, str);
+		build_trace_args_list(tmp, str);
 	}
 	smart_str_appends(str, ")\n");
 }
@@ -622,11 +619,10 @@ static void _build_trace_string(smart_str *str, const HashTable *ht, uint32_t nu
 /* {{{ Gets the function arguments printed as a string from a backtrace frame. */
 ZEND_API zend_string *zend_trace_function_args_to_string(const HashTable *frame) {
 	smart_str str = {0};
-	smart_str_appends(&str, "");
 
 	zval *tmp = zend_hash_find_known_hash(frame, ZSTR_KNOWN(ZEND_STR_ARGS));
 	if (tmp) {
-		_build_trace_args_list(tmp, &str);
+		build_trace_args_list(tmp, &str);
 	}
 
 	return smart_str_extract(&str);
@@ -640,12 +636,11 @@ ZEND_API zend_string *zend_trace_current_function_args_string(void) {
 	zval backtrace;
 	zend_fetch_debug_backtrace(&backtrace, /* skip_last */ 0, /* options */ 0, /* limit */ 1);
 	/* can fail esp if low memory condition */
-	if (Z_TYPE(backtrace) != IS_ARRAY) {
-		return NULL;
-	}
-	zval *first_frame = zend_hash_index_find(Z_ARRVAL(backtrace), 0);
-	if (first_frame) {
-		dynamic_params = zend_trace_function_args_to_string(Z_ARRVAL_P(first_frame));
+	if (Z_TYPE(backtrace) == IS_ARRAY) {
+		zval *first_frame = zend_hash_index_find(Z_ARRVAL(backtrace), 0);
+		if (first_frame) {
+			dynamic_params = zend_trace_function_args_to_string(Z_ARRVAL_P(first_frame));
+		}
 	}
 	zval_ptr_dtor(&backtrace);
 	return dynamic_params;
@@ -664,7 +659,7 @@ ZEND_API zend_string *zend_trace_to_string(const HashTable *trace, bool include_
 			continue;
 		}
 
-		_build_trace_string(&str, Z_ARRVAL_P(frame), num++);
+		build_trace_string(&str, Z_ARRVAL_P(frame), num++);
 	} ZEND_HASH_FOREACH_END();
 
 	if (include_main) {