From 4d7945f77871c2aeb1a2e702d03711db635ea472 Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Fri, 30 May 2025 07:01:03 -0500
Subject: [PATCH] XM import: possibly fix crash

thanks LTVA for diagnosis
issue #2453
---
 src/engine/fileOps/xm.cpp | 42 +++++++++++++++++++++++++++++++--------
 1 file changed, 34 insertions(+), 8 deletions(-)

diff --git a/src/engine/fileOps/xm.cpp b/src/engine/fileOps/xm.cpp
index 1e7330489..7579c04b5 100644
--- a/src/engine/fileOps/xm.cpp
+++ b/src/engine/fileOps/xm.cpp
@@ -162,13 +162,18 @@ void readEnvelope(DivInstrument* ins, int env, unsigned char flags, unsigned cha
   }
 }
 
+#define XM_FINISH \
+  delete[] sampleVol; \
+  delete[] samplePan; \
+  delete[] noteMap;
+
 bool DivEngine::loadXM(unsigned char* file, size_t len) {
   struct InvalidHeaderException {};
   bool success=false;
   char magic[32];
-  unsigned char sampleVol[256][256];
-  unsigned char samplePan[256][256];
-  unsigned char noteMap[256][128];
+  unsigned char* sampleVol=new unsigned char[256*256];
+  unsigned char* samplePan=new unsigned char[256*256];
+  unsigned char* noteMap=new unsigned char[256*128];
 
   unsigned short patLen[256];
 
@@ -216,6 +221,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
       logE("premature end of file!");
       lastError="incomplete file";
       delete[] file;
+      XM_FINISH;
       return false;
     }
     reader.read(magic,17);
@@ -255,6 +261,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
       logE("invalid order count!");
       lastError="invalid order count";
       delete[] file;
+      XM_FINISH;
       return false;
     }
 
@@ -262,6 +269,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
       logE("too many patterns!");
       lastError="too many patterns";
       delete[] file;
+      XM_FINISH;
       return false;
     }
 
@@ -269,6 +277,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
       logE("invalid instrument count!");
       lastError="invalid instrument count";
       delete[] file;
+      XM_FINISH;
       return false;
     }
 
@@ -278,6 +287,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
       logE("invalid channel count!");
       lastError="invalid channel count";
       delete[] file;
+      XM_FINISH;
       return false;
     }
 
@@ -306,6 +316,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
       logE("premature end of file!");
       lastError="incomplete file";
       delete[] file;
+      XM_FINISH;
       return false;
     }
 
@@ -322,6 +333,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         lastError="unknown packing type";
         ds.unload();
         delete[] file;
+        XM_FINISH;
         return false;
       }
 
@@ -334,6 +346,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         logE("too many rows! %d",totalRows);
         lastError="too many rows";
         delete[] file;
+        XM_FINISH;
         return false;
       }
 
@@ -344,6 +357,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         logE("premature end of file!");
         lastError="incomplete file";
         delete[] file;
+        XM_FINISH;
         return false;
       }
 
@@ -491,6 +505,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         logE("premature end of file!");
         lastError="incomplete file";
         delete[] file;
+        XM_FINISH;
         return false;
       }
     }
@@ -518,6 +533,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         delete ins;
         song.unload();
         delete[] file;
+        XM_FINISH;
         return false;
       }*/
 
@@ -532,7 +548,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         for (int j=0; j<96; j++) {
           unsigned char nextMap=reader.readC();
           ins->amiga.noteMap[j].map=ds.sample.size()+nextMap;
-          noteMap[i][j]=nextMap;
+          noteMap[(i<<7)|j]=nextMap;
         }
 
         for (int j=0; j<24; j++) {
@@ -611,6 +627,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
           logE("premature end of file!");
           lastError="incomplete file";
           delete[] file;
+          XM_FINISH;
           return false;
         }
 
@@ -625,17 +642,18 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
             lastError="bad sample size";
             delete s;
             delete[] file;
+            XM_FINISH;
             return false;
           }
 
           s->loopStart=reader.readI();
           s->loopEnd=reader.readI()+s->loopStart;
 
-          sampleVol[i][j]=reader.readC();
+          sampleVol[(i<<8)|j]=reader.readC();
 
           signed char fine=reader.readC();
           unsigned char flags=reader.readC();
-          samplePan[i][j]=reader.readC();
+          samplePan[(i<<8)|j]=reader.readC();
           signed char note=reader.readC();
 
           switch (flags&3) {
@@ -706,6 +724,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
           logE("premature end of file!");
           lastError="incomplete file";
           delete[] file;
+          XM_FINISH;
           return false;
         }
       }
@@ -717,6 +736,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
       logE("premature end of file!");
       lastError="incomplete file";
       delete[] file;
+      XM_FINISH;
       return false;
     }
 
@@ -799,6 +819,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         lastError="unknown packing type";
         ds.unload();
         delete[] file;
+        XM_FINISH;
         return false;
       }
 
@@ -811,6 +832,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         logE("too many rows! %d",totalRows);
         lastError="too many rows";
         delete[] file;
+        XM_FINISH;
         return false;
       }
 
@@ -821,6 +843,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         logE("premature end of file!");
         lastError="incomplete file";
         delete[] file;
+        XM_FINISH;
         return false;
       }
 
@@ -880,7 +903,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
             p->data[j][2]=((int)ins)-1;
             // default volume
             if (lastNote[k]<96 && ins>0) {
-              p->data[j][3]=sampleVol[(ins-1)&255][noteMap[(ins-1)&255][lastNote[k]&127]];
+              p->data[j][3]=sampleVol[(((ins-1)&255)<<8)|(noteMap[(((ins-1)&255)<<7)|(lastNote[k]&127)])];
             }
             writePanning=true;
           }
@@ -1189,7 +1212,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
 
           if (writePanning && hasNote && note<96 && ins>0) {
             p->data[j][effectCol[k]++]=0x80;
-            p->data[j][effectCol[k]++]=samplePan[(ins-1)&255][noteMap[(ins-1)&255][note&127]];
+            p->data[j][effectCol[k]++]=samplePan[(((ins-1)&255)<<8)|(noteMap[(((ins-1)&255)<<7)|(note&127)])];
           }
         }
 
@@ -1305,6 +1328,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
         logE("premature end of file!");
         lastError="incomplete file";
         delete[] file;
+        XM_FINISH;
         return false;
       }
     }
@@ -1315,6 +1339,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
       lastError="too many samples";
       ds.unload();
       delete[] file;
+      XM_FINISH;
       return false;
     }
 
@@ -1351,6 +1376,7 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
     //logE("invalid header!");
     lastError="invalid header!";
   }
+  XM_FINISH;
   return success;
 }