* ARPACK routines (at least dnaupd) modifieD its argument TOL, which

is listed in the documentation as input-only. Thanks to Pauli Virtanen
     for the patch (Closes: #632)

SRC/dnaup2.f

@@ -664,6 +664,17 @@ c
             else if (nev .eq. 1 .and. kplusp .gt. 3) then
                nev = 2
             end if
+c           %---- Scipy fix ------------------------------------------------
+c           | We must keep nev below this value, as otherwise we can get
+c           | np == 0 (note that dngets below can bump nev by 1). If np == 0,
+c           | the next call to `dnaitr` will write out-of-bounds.
+c           |
+            if (nev .gt. kplusp - 2) then
+               nev = kplusp - 2
+            end if
+c           |
+c           %---- Scipy fix end --------------------------------------------
+c
             np = kplusp - nev
 c
 c           %---------------------------------------%

SRC/snaup2.f

@@ -664,6 +664,18 @@ c
             else if (nev .eq. 1 .and. kplusp .gt. 3) then
                nev = 2
             end if
+c           %---- Scipy fix ------------------------------------------------
+c           | We must keep nev below this value, as otherwise we can get
+c           | np == 0 (note that sngets below can bump nev by 1). If np == 0,
+c           | the next call to `snaitr` will write out-of-bounds.
+c           |
+            if (nev .gt. kplusp - 2) then
+               nev = kplusp - 2
+            end if
+c           |
+c           %---- Scipy fix end --------------------------------------------
+
+c
             np = kplusp - nev
 c
 c           %---------------------------------------%