ENH: sparse/dsolve: re-apply patches on top of SuperLU 4.3

    - Hook up USER_* routines to Scipy

    - Fix a dubious format string

    - Sprinkle volatile into dlamc/slamc implementation to avoid an infinite loop

    - Eliminate a crash for singular matrices for which pivoting fails

    - Do not exit(1) when ILU decomposition encounters singularity;
      instead call ABORT (which is hooked up in Scipy)

    - Add missing declarations of dlamch_ (call without declaration to
      functions returning floating point can cause NaN to appear later on, on i386).

diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/cpivotL.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/cpivotL.c
index a14ea72..f60c4dc 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/cpivotL.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/cpivotL.c
@@ -125,7 +125,16 @@ if ( jcol == MIN_COL ) {
     /* Test for singularity */
     if ( pivmax == 0.0 ) {
 #if 1
+#if SCIPY_FIX
+	if (pivptr < nsupr) {
+	    *pivrow = lsub_ptr[pivptr];
+	}
+	else {
+	    *pivrow = diagind;
+	}
+#else
 	*pivrow = lsub_ptr[pivptr];
+#endif
 	perm_r[*pivrow] = jcol;
 #else
 	perm_r[diagind] = jcol;
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/dlamch.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/dlamch.c
index 678ac35..e117915 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/dlamch.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/dlamch.c
@@ -673,9 +673,13 @@ double dlamc3_(double *a, double *b)
 {
 /* >>Start of File<<   
        System generated locals */
-    double ret_val;
+    volatile double ret_val;
+    volatile double x;
+    volatile double y;
 
-    ret_val = *a + *b;
+    x = *a;
+    y = *b;
+    ret_val = x + y;
 
     return ret_val;
 
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/dpivotL.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/dpivotL.c
index bcfa96d..6a66068 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/dpivotL.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/dpivotL.c
@@ -124,7 +124,16 @@ if ( jcol == MIN_COL ) {
     /* Test for singularity */
     if ( pivmax == 0.0 ) {
 #if 1
+#if SCIPY_FIX
+	if (pivptr < nsupr) {
+	    *pivrow = lsub_ptr[pivptr];
+	}
+	else {
+	    *pivrow = diagind;
+	}
+#else
 	*pivrow = lsub_ptr[pivptr];
+#endif
 	perm_r[*pivrow] = jcol;
 #else
 	perm_r[diagind] = jcol;
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_ccopy_to_ucol.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_ccopy_to_ucol.c
index b6b0328..5a7203d 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_ccopy_to_ucol.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_ccopy_to_ucol.c
@@ -17,6 +17,9 @@ int num_drop_U;
 #endif
 
 extern void ccopy_(int *, complex [], int *, complex [], int *);
+#if SCIPY_FIX
+extern double dlamch_(char *);
+#endif
 
 #if 0
 static complex *A;  /* used in _compare_ only */
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_cpivotL.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_cpivotL.c
index d806485..98991d7 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_cpivotL.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_cpivotL.c
@@ -136,9 +136,13 @@ ilu_cpivotL(
 
     /* Test for singularity */
     if (pivmax < 0.0) {
+#if SCIPY_FIX
+	ABORT("[0]: matrix is singular");
+#else
 	fprintf(stderr, "[0]: jcol=%d, SINGULAR!!!\n", jcol);
 	fflush(stderr);
 	exit(1);
+#endif
     }
     if ( pivmax == 0.0 ) {
 	if (diag != EMPTY)
@@ -151,9 +155,13 @@ ilu_cpivotL(
 	    for (icol = jcol; icol < n; icol++)
 		if (marker[swap[icol]] <= jcol) break;
 	    if (icol >= n) {
+#if SCIPY_FIX
+		ABORT("[1]: matrix is singular");
+#else
 		fprintf(stderr, "[1]: jcol=%d, SINGULAR!!!\n", jcol);
 		fflush(stderr);
 		exit(1);
+#endif
 	    }
 
 	    *pivrow = swap[icol];
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_dpivotL.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_dpivotL.c
index 33c316d..0cbb21d 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_dpivotL.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_dpivotL.c
@@ -134,9 +134,13 @@ ilu_dpivotL(
 
     /* Test for singularity */
     if (pivmax < 0.0) {
+#if SCIPY_FIX
+	ABORT("[0]: matrix is singular");
+#else
 	fprintf(stderr, "[0]: jcol=%d, SINGULAR!!!\n", jcol);
 	fflush(stderr);
 	exit(1);
+#endif
     }
     if ( pivmax == 0.0 ) {
 	if (diag != EMPTY)
@@ -149,9 +153,13 @@ ilu_dpivotL(
 	    for (icol = jcol; icol < n; icol++)
 		if (marker[swap[icol]] <= jcol) break;
 	    if (icol >= n) {
+#if SCIPY_FIX
+		ABORT("[1]: matrix is singular");
+#else
 		fprintf(stderr, "[1]: jcol=%d, SINGULAR!!!\n", jcol);
 		fflush(stderr);
 		exit(1);
+#endif
 	    }
 
 	    *pivrow = swap[icol];
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_scopy_to_ucol.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_scopy_to_ucol.c
index 7e0e97c..b9fd387 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_scopy_to_ucol.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_scopy_to_ucol.c
@@ -17,6 +17,9 @@ int num_drop_U;
 #endif
 
 extern void scopy_(int *, float [], int *, float [], int *);
+#if SCIPY_FIX
+extern double dlamch_(char *);
+#endif
 
 #if 0
 static float *A;  /* used in _compare_ only */
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_spivotL.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_spivotL.c
index 25b6b00..ff36657 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_spivotL.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_spivotL.c
@@ -134,9 +134,13 @@ ilu_spivotL(
 
     /* Test for singularity */
     if (pivmax < 0.0) {
+#if SCIPY_FIX
+	ABORT("[0]: matrix is singular");
+#else
 	fprintf(stderr, "[0]: jcol=%d, SINGULAR!!!\n", jcol);
 	fflush(stderr);
 	exit(1);
+#endif
     }
     if ( pivmax == 0.0 ) {
 	if (diag != EMPTY)
@@ -149,9 +153,13 @@ ilu_spivotL(
 	    for (icol = jcol; icol < n; icol++)
 		if (marker[swap[icol]] <= jcol) break;
 	    if (icol >= n) {
+#if SCIPY_FIX
+		ABORT("[1]: matrix is singular");
+#else
 		fprintf(stderr, "[1]: jcol=%d, SINGULAR!!!\n", jcol);
 		fflush(stderr);
 		exit(1);
+#endif
 	    }
 
 	    *pivrow = swap[icol];
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_zpivotL.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_zpivotL.c
index dafea2b..4ea86b1 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_zpivotL.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/ilu_zpivotL.c
@@ -136,9 +136,13 @@ ilu_zpivotL(
 
     /* Test for singularity */
     if (pivmax < 0.0) {
+#if SCIPY_FIX
+	ABORT("[0]: matrix is singular");
+#else
 	fprintf(stderr, "[0]: jcol=%d, SINGULAR!!!\n", jcol);
 	fflush(stderr);
 	exit(1);
+#endif
     }
     if ( pivmax == 0.0 ) {
 	if (diag != EMPTY)
@@ -151,9 +155,13 @@ ilu_zpivotL(
 	    for (icol = jcol; icol < n; icol++)
 		if (marker[swap[icol]] <= jcol) break;
 	    if (icol >= n) {
+#if SCIPY_FIX
+		ABORT("[1]: matrix is singular");
+#else
 		fprintf(stderr, "[1]: jcol=%d, SINGULAR!!!\n", jcol);
 		fflush(stderr);
 		exit(1);
+#endif
 	    }
 
 	    *pivrow = swap[icol];
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/scipy_slu_config.h b/scipy/sparse/linalg/dsolve/SuperLU/SRC/scipy_slu_config.h
new file mode 100644
index 0000000..5afc93b
--- /dev/null
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/scipy_slu_config.h
@@ -0,0 +1,36 @@
+#ifndef SCIPY_SLU_CONFIG_H
+#define SCIPY_SLU_CONFIG_H
+
+#include <stdlib.h>
+
+/*
+ * Support routines
+ */
+void superlu_python_module_abort(char *msg);
+void *superlu_python_module_malloc(size_t size);
+void superlu_python_module_free(void *ptr);
+
+#define USER_ABORT  superlu_python_module_abort
+#define USER_MALLOC superlu_python_module_malloc
+#define USER_FREE   superlu_python_module_free
+
+#define SCIPY_FIX 1
+
+/*
+ * Fortran configuration
+ */
+#if defined(NO_APPEND_FORTRAN)
+#if defined(UPPERCASE_FORTRAN)
+#define UpCase 1
+#else
+#define NoChange 1
+#endif
+#else
+#if defined(UPPERCASE_FORTRAN)
+#error Uppercase and trailing slash in Fortran names not supported
+#else
+#define Add_ 1
+#endif
+#endif
+
+#endif
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/slamch.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/slamch.c
index ec3cd61..09cf6e2 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/slamch.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/slamch.c
@@ -684,11 +684,13 @@ double slamc3_(float *a, float *b)
 
 /* >>Start of File<<   
        System generated locals */
-    float ret_val;
-
-
+    volatile float ret_val;
+    volatile float x;
+    volatile float y;
 
-    ret_val = *a + *b;
+    x = *a;
+    y = *b;
+    ret_val = x + y;
 
     return ret_val;
 
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/slu_Cnames.h b/scipy/sparse/linalg/dsolve/SuperLU/SRC/slu_Cnames.h
index 7bcd1bc..80b8aa1 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/slu_Cnames.h
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/slu_Cnames.h
@@ -19,6 +19,7 @@
 #ifndef __SUPERLU_CNAMES /* allow multiple inclusions */
 #define __SUPERLU_CNAMES
 
+#include "scipy_slu_config.h"
 
 #define ADD_       0
 #define ADD__      1
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/slu_util.h b/scipy/sparse/linalg/dsolve/SuperLU/SRC/slu_util.h
index 30b5f9b..f41b4ca 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/slu_util.h
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/slu_util.h
@@ -22,6 +22,8 @@
 #include <assert.h>
 #include "superlu_enum_consts.h"
 
+#include "scipy_slu_config.h"
+
 /***********************************************************************
  * Macros
  ***********************************************************************/
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/spivotL.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/spivotL.c
index 2a6950c..a9f0de5 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/spivotL.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/spivotL.c
@@ -124,7 +124,16 @@ if ( jcol == MIN_COL ) {
     /* Test for singularity */
     if ( pivmax == 0.0 ) {
 #if 1
+#if SCIPY_FIX
+	if (pivptr < nsupr) {
+	    *pivrow = lsub_ptr[pivptr];
+	}
+	else {
+	    *pivrow = diagind;
+	}
+#else
 	*pivrow = lsub_ptr[pivptr];
+#endif
 	perm_r[*pivrow] = jcol;
 #else
 	perm_r[diagind] = jcol;
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/util.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/util.c
index 858fbbc..4c19e77 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/util.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/util.c
@@ -29,7 +29,7 @@
 
 void superlu_abort_and_exit(char* msg)
 {
-    fprintf(stderr, msg);
+    fprintf(stderr, "%s\n", msg);
     exit (-1);
 }
 
diff --git a/scipy/sparse/linalg/dsolve/SuperLU/SRC/zpivotL.c b/scipy/sparse/linalg/dsolve/SuperLU/SRC/zpivotL.c
index ce4f513..e134896 100644
--- a/scipy/sparse/linalg/dsolve/SuperLU/SRC/zpivotL.c
+++ b/scipy/sparse/linalg/dsolve/SuperLU/SRC/zpivotL.c
@@ -125,7 +125,16 @@ if ( jcol == MIN_COL ) {
     /* Test for singularity */
     if ( pivmax == 0.0 ) {
 #if 1
+#if SCIPY_FIX
+	if (pivptr < nsupr) {
+	    *pivrow = lsub_ptr[pivptr];
+	}
+	else {
+	    *pivrow = diagind;
+	}
+#else
 	*pivrow = lsub_ptr[pivptr];
+#endif
 	perm_r[*pivrow] = jcol;
 #else
 	perm_r[diagind] = jcol;