diff --git a/xwords4/linux/linuxdict.c b/xwords4/linux/linuxdict.c
index 30c909732..b41a0ddde 100644
--- a/xwords4/linux/linuxdict.c
+++ b/xwords4/linux/linuxdict.c
@@ -221,27 +221,28 @@ dict_splitFaces( DictionaryCtxt* dict, const XP_U8* utf8,
     XP_U16 ii;
     XP_Bool isUTF8 = dict->isUTF8;
     XP_UCHAR* next = faces;
-    const gchar* bytes = (const gchar*)utf8;
+    const gchar* bytesIn = (const gchar*)utf8;
+    const gchar* bytesEnd = bytesIn + nBytes;
 
     for ( ii = 0; ii < nFaces; ++ii ) {
         ptrs[ii] = next;
         if ( isUTF8 ) {
             for ( ; ; ) {
-                gchar* cp = g_utf8_offset_to_pointer( bytes, 1 );
-                size_t len = cp - bytes;
-                XP_MEMCPY( next, bytes, len );
+                gchar* cp = g_utf8_offset_to_pointer( bytesIn, 1 );
+                size_t len = cp - bytesIn;
+                XP_MEMCPY( next, bytesIn, len );
                 next += len;
-                bytes += len;
-                if ( SYNONYM_DELIM != bytes[0] ) {
+                bytesIn += len;
+                if ( bytesIn >= bytesEnd || SYNONYM_DELIM != bytesIn[0] ) {
                     break;
                 }
-                ++bytes;        /* skip delimiter */
+                ++bytesIn;        /* skip delimiter */
                 *next++ = '\0';
             }
         } else {
-            XP_ASSERT( 0 == *bytes );
-            ++bytes;            /* skip empty */
-            *next++ = *bytes++;
+            XP_ASSERT( 0 == *bytesIn );
+            ++bytesIn;            /* skip empty */
+            *next++ = *bytesIn++;
         }
         XP_ASSERT( next < faces + nFaces + nBytes );
         *next++ = '\0';
diff --git a/xwords4/linux/linuxmain.c b/xwords4/linux/linuxmain.c
index 3c992e2b6..19608eab5 100644
--- a/xwords4/linux/linuxmain.c
+++ b/xwords4/linux/linuxmain.c
@@ -83,11 +83,15 @@ static int blocking_read( int fd, unsigned char* buf, const int len );
 XP_Bool
 file_exists( const char* fileName )
 {
-    struct stat statBuf;
+    XP_Bool exists = !!fileName;
+    if ( exists ) {
+        struct stat statBuf;
 
-    int statResult = stat( fileName, &statBuf );
-    // XP_LOGF( "%s(%s)=>%d", __func__, fileName, statResult == 0 );
-    return statResult == 0;
+        int statResult = stat( fileName, &statBuf );
+        // XP_LOGF( "%s(%s)=>%d", __func__, fileName, statResult == 0 );
+        exists = statResult == 0;
+    }
+    return exists;
 } /* file_exists */
 
 XWStreamCtxt*