misc: Handle M_StringCopy() short buffer case.

M_StringCopy() must always be provided a buffer of at least one
character long, so that a NUL character can be written. If this is
not the case, return immediately and indicate that the buffer was
truncated.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/m_misc.c b/src/m_misc.c
index ab3c7009..53b86dba 100644
--- a/src/m_misc.c
+++ b/src/m_misc.c
@@ -379,6 +379,11 @@ boolean M_StringCopy(char *dest, const char *src, size_t dest_size)
         dest[dest_size - 1] = '\0';
         strncpy(dest, src, dest_size - 1);
     }
+    else
+    {
+        return false;
+    }
+
     len = strlen(dest);
     return src[len] == '\0';
 }