--- jhead.c.orig        2008-11-01 16:31:28.000000000 +0100
+++ jhead.c     2008-11-03 09:36:23.000000000 +0100
@@ -335,10 +335,16 @@
 
     e = 0;
 
-    // Make a temporary file in the destination directory by changing last char.
-    strcpy(TempName, FileName);
-    a = strlen(TempName)-1;
-    TempName[a] = (char)(TempName[a] == 't' ? 'z' : 't');
+    // Generate an unused temporary file name in the destination directory
+    // (a is the number of characters to copy from FileName)
+    a = strlen(FileName)-1;
+    while(a > 0 && FileName[a-1] != '/') a--;
+    memcpy(TempName, FileName, a);
+    strcpy(TempName+a, "XXXXXX");
+    mktemp(TempName);
+    if(!TempName[0]) {
+        ErrFatal("Cannot find available temporary file name");
+    }
 
     // Build the exec string.  &i and &o in the exec string get replaced by input and output files.
     for (a=0;;a++){
@@ -354,7 +360,6 @@
                 e += shellescape(ExecString+e, TempName);
                 a += 1;
                 TempUsed = TRUE;
-                unlink(TempName);// Remove any pre-existing temp file
                 continue;
             }
         }