diff --git a/include/ft/test.h b/include/ft/test.h
index 082ff44..e8ffc22 100644
--- a/include/ft/test.h
+++ b/include/ft/test.h
@@ -40,12 +40,21 @@ void ft_test_run(ft_test *test);
 /* ft_test_done(): Check whether a test is done */
 bool ft_test_done(ft_test *test);
 
-/* ft_assert(): Record an assertion in a test */
-void ft_assert(ft_test *test, int expression,
+/* ft_assert(): Record an assertion in a test, return value */
+int ft_assert(ft_test *test, int expression,
     char const *file, int line, char const *expression_str);
 #define ft_assert(test, expression) \
     ft_assert(test, expression, __FILE__, __LINE__, #expression)
 
+/* ft_assert_eval(): Evaluate expression, log result and assert result */
+#define ft_assert_eval(test, expression, expected, resultfmt) { \
+    if(ft_assert(test, (expression) == (expected))) \
+        ft_log(test, #expression " = " #expected "\n"); \
+    else \
+        ft_log(test, #expression " = " resultfmt " [wanted " #expected "]\n", \
+            (expression)); \
+}
+
 /* ft_log(): Write some data in a test's log */
 __attribute__((format(printf, 2, 3)))
 void ft_log(ft_test *test, char const *format, ...);
diff --git a/src/main.c b/src/main.c
index ff2cc5b..260d64b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -70,7 +70,7 @@ int main(void)
     gscreen_set_tab_fkeys_visible(scr, 1, false);
 
     flog *testlog = flog_create(NULL);
-    flog_set_line_spacing(testlog, 2);
+    flog_set_line_spacing(testlog, 3);
     gscreen_add_tab(scr, testlog, testlog);
     gscreen_set_tab_fkeys_visible(scr, 2, false);
 
diff --git a/src/test.c b/src/test.c
index 82096d2..01f40c2 100644
--- a/src/test.c
+++ b/src/test.c
@@ -29,7 +29,7 @@ bool ft_test_done(ft_test *test)
     return test->passed + test->skipped + test->failed > 0;
 }
 
-void ft_assert(ft_test *test, int expression, char const *file, int line,
+int ft_assert(ft_test *test, int expression, char const *file, int line,
     char const *str)
 {
     if(expression) {
@@ -39,6 +39,7 @@ void ft_assert(ft_test *test, int expression, char const *file, int line,
         test->failed++;
         ft_log(test, "%s:%d: assertion failed:\n  %s\n", file, line, str);
     }
+    return expression;
 }
 
 void ft_log(ft_test *test, char const *format, ...)
diff --git a/src/widgets/flog.c b/src/widgets/flog.c
index 8ddff5a..676c972 100644
--- a/src/widgets/flog.c
+++ b/src/widgets/flog.c
@@ -34,6 +34,7 @@ void flog_set_log(flog *l, char const *log, int log_size)
 
     l->log = log;
     l->log_size = log_size;
+    l->top = 0;
     l->widget.dirty = 1;
 }
 
@@ -105,8 +106,13 @@ static void flog_poly_render(void *l0, int x, int y)
     int current_line = 0;
     int current_y = y;
 
+
     while(log < l->log + l->log_size)
     {
+        if(current_line >= l->top && current_line < l->top + l->visible)
+            dprint_opt(x+22, current_y, C_BLACK, C_NONE,
+                DTEXT_RIGHT, DTEXT_TOP, "%d", current_line+1);
+
         if(log[0] == '\n') {
             log++;
         }
@@ -115,19 +121,19 @@ static void flog_poly_render(void *l0, int x, int y)
             char const *endline = strchrnul(log, '\n');
             int len = max(1, min(endscreen-log, endline-log));
 
-            if(current_line >= l->top && current_line < l->top + l->visible) {
-                dprint_opt(x+22, current_y, C_RGB(21,21,21), C_NONE,
-                    DTEXT_RIGHT, DTEXT_TOP, "%d", current_line+1);
-                dtext_opt(x+28, current_y, C_BLACK, C_NONE, DTEXT_LEFT,
+            if(current_line >= l->top && current_line < l->top + l->visible)
+                dtext_opt(x+30, current_y, C_BLACK, C_NONE, DTEXT_LEFT,
                     DTEXT_TOP, log, len);
-            }
 
             log += len + (log[len] == '\n');
         }
 
-        current_line++;
-        if(current_line > l->top)
+        if(current_line >= l->top && current_line < l->top + l->visible) {
+            int previous_y = current_y;
             current_y += l->font->line_height + l->line_spacing;
+            dline(x+26, previous_y, x+26, current_y-1, C_BLACK);
+        }
+        current_line++;
     }
 
     if(current_line > l->visible) {
@@ -163,7 +169,7 @@ static bool flog_poly_event(void *l0, jevent e)
         return true;
     }
     if(key == KEY_DOWN) {
-        l->top = min(l->lines - l->visible, l->top + scroll_speed);
+        l->top = max(0, min(l->lines - l->visible, l->top + scroll_speed));
         l->widget.update = 1;
         return true;
     }