Add -Wshadow to tool build flags.

And fixes a shadowed (but harmless) loop counter warning.

tool

@@ -209,7 +209,9 @@ build_target() {
   local out_exe
   add cc_flags -std=c99 -pipe -finput-charset=UTF-8 -Wall -Wpedantic -Wextra
   if cc_id_and_vers_gte gcc 6.0.0 || cc_id_and_vers_gte clang 3.9.0; then
-    add cc_flags -Wconversion -Wstrict-prototypes -Werror=implicit-function-declaration -Werror=implicit-int -Werror=incompatible-pointer-types -Werror=int-conversion
+    add cc_flags -Wconversion -Wshadow -Wstrict-prototypes \
+      -Werror=implicit-function-declaration -Werror=implicit-int \
+      -Werror=incompatible-pointer-types -Werror=int-conversion
   fi
   if [[ $lld_detected = 1 ]]; then
     add cc_flags -fuse-ld=lld

tui_main.c

@@ -588,8 +588,8 @@ void draw_oevent_list(WINDOW* win, Oevent_list const* oevent_list) {
       Oevent_osc_ints const* eo = &ev->osc_ints;
       wprintw(win, "OSC\t%c\tcount: %d ", eo->glyph, eo->count, eo->count);
       waddch(win, ACS_VLINE);
-      for (Usz i = 0; i < eo->count; ++i) {
-        wprintw(win, " %d", eo->numbers[i]);
+      for (Usz j = 0; j < eo->count; ++i) {
+        wprintw(win, " %d", eo->numbers[j]);
       }
     } break;
     case Oevent_type_udp_string: {