--- netpbm-svn-4903.old/editor/pnmremap.c
+++ netpbm-svn-4903/editor/pnmremap.c
@@ -400,13 +400,54 @@
    Set a random error in the range [-1 .. 1] (normalized via FS_SCALE)
    in the error array err[][].
 -----------------------------------------------------------------------------*/
+
     unsigned int col;
+    int c;
+    char *cp;
+    unsigned long x_seed;
     struct pm_randSt randSt;
 
     assert(random.init != RANDOM_NONE);
+    x_seed = random.seed;
+
+/* ------------------------------------------------------------ */
+
+/* This version  of  "pnmremap.c" supports an environment vari- */
+/* able named PNMREMAPRAND. If the variable is defined, and its */
+/* value starts with "f" or "F" [short for FALSE] or "n" or "N" */
+/* [short for "NO"],  "pnmremap.c"  uses a fixed  random-number */
+/* seed.                                                        */
+
+/* The PNMREMAPRAND feature was  added for the benefit of a new */
+/* program named "ppmquantnr". The new program is equivalent to */
+/* the existing  "ppmquant" program, with one difference: "ppm- */
+/* quantnr" sets PNMREMAPRAND to NO.  The change means that the */
+/* user will get consistent  results  if he or she executes the */
+/* same  "ppmquantnr" command  repeatedly  for identical  input */
+/* files at different times.  This is a useful feature for some */
+/* applications.                                                */
+
+/* As of 2019,  "pnmremap.c" seems to include a similar feature */
+/* of its own.  The PNMREMAPRAND feature will be retained,  re- */
+/* gardless, for the sake of backwards compatibility.           */
+
+    c = 0;
+
+    if ((cp = getenv ("PNMREMAPRAND")) != NULL)
+    {
+        c = *cp;
+        if ((c >= 'a') && (c <= 'z')) c += 'A' - 'a';
+    }
+                                /* Produce consistent results?  */
+    if ((c == 'F') || (c == 'N'))
+    {                           /* Yes                          */
+        x_seed = 0x3DBA656FL;
+    }
+
+/* ------------------------------------------------------------ */
 
-    pm_randinit(&randSt);
-    pm_srand2(&randSt, random.init == RANDOM_WITHSEED, random.seed);
+    pm_randinit (&randSt);
+    pm_srand2 (&randSt, random.init == RANDOM_WITHSEED, x_seed);
 
     for (col = 0; col < width; ++col) {
         unsigned int plane;