Fix memory leak in FindFontSet

Valgrind results before:

  definitely lost: 800 bytes in 23 blocks
  indirectly lost: 872 bytes in 6 blocks
    possibly lost: 0 bytes in 0 blocks
  still reachable: 991,316 bytes in 1,795 blocks
       suppressed: 0 bytes in 0 blocks

Valgrind results after:

  definitely lost: 200 bytes in 17 blocks
  indirectly lost: 0 bytes in 0 blocks
    possibly lost: 0 bytes in 0 blocks
  still reachable: 918,812 bytes in 994 blocks
       suppressed: 0 bytes in 0 blocks

Signed-off-by: Tim Wiederhake <twied@gmx.net>
Part-of: <https://gitlab.freedesktop.org/xorg/app/twm/-/merge_requests/29>

1 files changed, 19 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
index 9a04ac1..52f6148 100644
--- a/src/util.c
+++ b/src/util.c
@@ -607,6 +607,7 @@ FindFontSet(MyFont *font, const char *fontname)
                 twmVerbose("font for charset %s is lacking.",
                            missing_charset_list_return[i]);
             }
+            XFreeStringList(missing_charset_list_return);
         }
 
         font_extents = XExtentsOfFontSet(font->fontset);
@@ -672,6 +673,24 @@ GetFont(MyFont *font)
     }
 }
 
+void
+DestroyFont(MyFont *font)
+{
+    if (!font) {
+        return;
+    }
+
+    if (font->fontset) {
+        XFreeFontSet(dpy, font->fontset);
+        font->fontset = NULL;
+    }
+
+    if (font->font) {
+        XFreeFont(dpy, font->font);
+        font->font = NULL;
+    }
+}
+
 int
 MyFont_TextWidth(MyFont *font, const char *string, int len)
 {