[cff, pshinter] Clean up unsigned counters.

Loops with unsigned decrement can be reliably stopped when the counter
wraps around after reaching zero.

* src/cff/cffload.c (cff_charset_compute_cids): Use unsigned counter.
* src/pshinter/pshalgo.c (psh_hint_table_activate_mask): Ditto.
* src/pshinter/pshrec.c (ps_mask_table_merge): Ditto.

src/cff/cffload.c

@@ -835,7 +835,6 @@
   {
     FT_Error   error   = FT_Err_Ok;
     FT_UInt    i;
-    FT_Long    j;
     FT_UShort  max_cid = 0;
 
 
@@ -853,9 +852,10 @@
 
     /* When multiple GIDs map to the same CID, we choose the lowest */
     /* GID.  This is not described in any spec, but it matches the  */
-    /* behaviour of recent Acroread versions.                       */
-    for ( j = (FT_Long)num_glyphs - 1; j >= 0; j-- )
-      charset->cids[charset->sids[j]] = (FT_UShort)j;
+    /* behaviour of recent Acroread versions.  The loop stops when  */
+    /* the unsigned index wraps around after reaching zero.         */
+    for ( i = num_glyphs - 1; i < num_glyphs; i-- )
+      charset->cids[charset->sids[i]] = (FT_UShort)i;
 
     charset->max_cid    = max_cid;
     charset->num_glyphs = num_glyphs;

src/pshinter/pshalgo.c

@@ -305,17 +305,18 @@
     /* now, sort the hints; they are guaranteed to not overlap */
     /* so we can compare their "org_pos" field directly        */
     {
-      FT_Int     i1, i2;
+      FT_UInt    i1, i2;
       PSH_Hint   hint1, hint2;
       PSH_Hint*  sort = table->sort;
 
 
       /* a simple bubble sort will do, since in 99% of cases, the hints */
       /* will be already sorted -- and the sort will be linear          */
-      for ( i1 = 1; i1 < (FT_Int)count; i1++ )
+      for ( i1 = 1; i1 < count; i1++ )
       {
         hint1 = sort[i1];
-        for ( i2 = i1 - 1; i2 >= 0; i2-- )
+        /* this loop stops when i2 wraps around after reaching 0 */
+        for ( i2 = i1 - 1; i2 < i1; i2-- )
         {
           hint2 = sort[i2];
 

src/pshinter/pshrec.c

@@ -499,23 +499,19 @@
   ps_mask_table_merge_all( PS_Mask_Table  table,
                            FT_Memory      memory )
   {
-    FT_Int    index1, index2;
+    FT_UInt   index1, index2;
     FT_Error  error = FT_Err_Ok;
 
 
-    /* both loops go down to 0, thus FT_Int for index1 and index2 */
-    for ( index1 = (FT_Int)table->num_masks - 1; index1 > 0; index1-- )
+    /* the inner loop stops when the unsigned index wraps around */
+    /* after reaching 0.                                         */
+    for ( index1 = table->num_masks - 1; index1 > 0; index1-- )
     {
-      for ( index2 = index1 - 1; index2 >= 0; index2-- )
+      for ( index2 = index1 - 1; index2 < index1; index2-- )
       {
-        if ( ps_mask_table_test_intersect( table,
-                                           (FT_UInt)index1,
-                                           (FT_UInt)index2 ) )
+        if ( ps_mask_table_test_intersect( table, index1, index2 ) )
         {
-          error = ps_mask_table_merge( table,
-                                       (FT_UInt)index2,
-                                       (FT_UInt)index1,
-                                       memory );
+          error = ps_mask_table_merge( table, index2, index1, memory );
           if ( error )
             goto Exit;