--- a/tools/xm2jss.c	Sun Aug 20 03:43:43 2017 +0300
+++ b/tools/xm2jss.c	Sun Aug 20 03:55:08 2017 +0300
@@ -788,7 +788,7 @@
          mapInstruments[jsetMaxInstruments + 1],
          mapPatterns[jsetMaxPatterns + 1];
     JSSModule *r = NULL;
-    int i, n8, n16, unused;
+    int n8, n16, nunused, ndupes;
 
     // Allocate a new module
     if ((r = jssAllocateModule()) == NULL)
@@ -806,14 +806,14 @@
     r->nchannels        = m->nchannels;
     r->norders          = m->norders;
 
-    for (i = 0; i < jsetNChannels; i++)
+    for (int i = 0; i < jsetNChannels; i++)
     {
         r->defPanning[i] = m->defPanning[i];
         usedChannels[i]  = FALSE;
     }
 
     // Initialize values
-    for (i = 0; i <= jsetMaxInstruments; i++)
+    for (int i = 0; i <= jsetMaxInstruments; i++)
     {
         usedExtInstruments[i] = FALSE;
         usedInstruments[i]    = FALSE;
@@ -821,7 +821,7 @@
         mapInstruments[i]     = jsetNotSet;
     }
 
-    for (i = 0; i <= jsetMaxPatterns; i++)
+    for (int i = 0; i <= jsetMaxPatterns; i++)
     {
         usedPatterns[i] = FALSE;
         mapPatterns[i]  = jsetNotSet;
@@ -832,9 +832,9 @@
     // by going through all patterns specified in the order list
     //
     dmMsg(1, "Scanning patterns for used instruments and channels...\n");
-    for (i = 0; i < m->norders; i++)
+    for (int norder = 0; norder < m->norders; norder++)
     {
-        int npat = m->orderList[i];
+        int npat = m->orderList[norder];
         if (npat >= 0 && npat < m->npatterns)
         {
             JSSPattern *pattern = m->patterns[npat];
@@ -851,27 +851,27 @@
                 // Empty patterns with known number of rows are "removed"
                 if (empty && pattern->nrows == jsetDefaultRows)
                 {
-                    m->orderList[i] = jsetNotSet;
+                    m->orderList[norder] = jsetNotSet;
                     usedPatterns[npat] = FALSE;
                 }
             }
             else
             {
                 dmErrorMsg("Pattern 0x%x is used on order 0x%x, but has no data!\n",
-                    npat, i);
+                    npat, norder);
 
                 // Fix it.
-                m->orderList[i] = jsetNotSet;
+                m->orderList[norder] = jsetNotSet;
             }
         }
         else
         if (npat != jsetNotSet)
         {
             dmErrorMsg("Order 0x%x has invalid pattern number 0x%x, changing to empty!\n",
-                i, npat);
+                norder, npat);
 
             // Fix it.
-            m->orderList[i] = jsetNotSet;
+            m->orderList[norder] = jsetNotSet;
         }
     }
 
@@ -879,7 +879,7 @@
     // Find used sample instruments
     //
     dmMsg(1, "Checking ext.instruments for used sample instruments...\n");
-    for (i = 0; i < jsetMaxInstruments; i++)
+    for (int i = 0; i < jsetMaxInstruments; i++)
     if (usedExtInstruments[i] && m->extInstruments[i] != NULL)
     {
         int note;
@@ -905,39 +905,41 @@
     // Create pattern mappings
     //
     dmMsg(1, "Creating pattern remaps...\n");
-    for (unused = i = 0; i <= jsetMaxPatterns; i++)
-    if (usedPatterns[i])
+    nunused = ndupes = 0;
+    for (int pat1 = 0; pat1 <= jsetMaxPatterns; pat1++)
+    if (usedPatterns[pat1])
     {
         JSSPattern *pat;
 
-        if (i >= m->npatterns)
+        if (pat1 >= m->npatterns)
         {
-            dmErrorMsg("Pattern 0x%x >= 0x%x, but used!\n", i, m->npatterns);
+            dmErrorMsg("Pattern 0x%x >= 0x%x, but used!\n", pat1, m->npatterns);
             continue;
         }
 
-        if ((pat = m->patterns[i]) == NULL)
+        if ((pat = m->patterns[pat1]) == NULL)
         {
-            dmErrorMsg("Pattern 0x%x used but is NULL.\n", i);
+            dmErrorMsg("Pattern 0x%x used but is NULL.\n", pat1);
             continue;
         }
 
-        mapPatterns[i] = r->npatterns;
-        r->patterns[r->npatterns] = m->patterns[i];
+        mapPatterns[pat1] = r->npatterns;
+        r->patterns[r->npatterns] = m->patterns[pat1];
         (r->npatterns)++;
     }
     else
-    if (m->patterns[i] != NULL)
-        unused++;
+    if (m->patterns[pat1] != NULL)
+        nunused++;
 
-    dmMsg(1, "%d used patterns (%d unused).\n",
-        r->npatterns, unused);
+    dmMsg(1, "%d used patterns (%d unused, %d duplicates).\n",
+        r->npatterns, nunused, ndupes);
 
     //
     // Re-map instruments
     //
     dmMsg(1, "Creating sample instrument remaps...\n");
-    for (unused = n8 = n16 = i = 0; i < jsetMaxInstruments; i++)
+    nunused = n8 = n16 = 0;
+    for (int i = 0; i < jsetMaxInstruments; i++)
     if (usedInstruments[i])
     {
         JSSInstrument *ip;
@@ -970,17 +972,18 @@
     }
     else
     if (m->instruments[i] != NULL)
-        unused++;
+        nunused++;
 
     dmPrint(2, "\n");
     dmMsg(1, "Total of %d [16-bit] + %d [8-bit] samples = %d instruments (%d unused).\n",
-        n16, n8, r->ninstruments, unused);
+        n16, n8, r->ninstruments, nunused);
 
     //
     // Re-map ext.instruments
     //
     dmMsg(1, "Creating ext.instrument remaps...\n");
-    for (unused = i = 0; i < jsetMaxInstruments; i++)
+    nunused = 0;
+    for (int i = 0; i < jsetMaxInstruments; i++)
     if (usedExtInstruments[i])
     {
         JSSExtInstrument *eip;
@@ -1032,16 +1035,16 @@
     }
     else
     if (m->extInstruments[i] != NULL)
-        unused++;
+        nunused++;
 
     dmPrint(2, "\n");
     dmMsg(1, "%d extended instruments (%d unused).\n",
-        r->nextInstruments, unused);
+        r->nextInstruments, nunused);
 
     //
     // Remap pattern data with remapped instrument data
     //
-    for (i = 0; i < r->npatterns; i++)
+    for (int i = 0; i < r->npatterns; i++)
     {
         int row, channel;
         JSSPattern *p = r->patterns[i];
@@ -1099,7 +1102,7 @@
     // Remap orders list
     //
     dmMsg(1, "Remapping orders list.\n");
-    for (i = 0; i < m->norders; i++)
+    for (int i = 0; i < m->norders; i++)
     {
         r->orderList[i] = mapPatterns[m->orderList[i]];
     }