mingle: use C++ 'nullptr' instead of C 'NULL'

diff --git a/cmd/mingle/minglemain.cpp b/cmd/mingle/minglemain.cpp
index 14ba56b5cf1fbffd10a20dd4db20564620d5c7ba..bb984b6b000f1897fab4ed67228ca8383ab58e28 100644 (file)
--- a/cmd/mingle/minglemain.cpp
+++ b/cmd/mingle/minglemain.cpp
@@ -95,7 +95,7 @@ checkG (Agraph_t* g)
        Agedge_t* e;
        Agnode_t* n;
        Agnode_t* h;
-       Agnode_t* prevh = NULL;
+       Agnode_t* prevh = nullptr;
 
        for (n = agfstnode (g); n; n = agnxtnode (g, n)) {
                for (e = agfstout (g, n); e; e = agnxtout (g, e)) {
@@ -103,7 +103,7 @@ checkG (Agraph_t* g)
                        if (h == prevh) return 1;            // multiedge
                        prevh = h;
                }
-               prevh = NULL;  // reset
+               prevh = nullptr;  // reset
        }
        return 0;
 }
@@ -331,7 +331,7 @@ export_dot (FILE* fp, int ne, pedge *edges, Agraph_t* g)
 {
        Agsym_t* epos = agattr(g, AGEDGE, (char*)"pos", "");
        Agsym_t* esects = agattr(g, AGEDGE, (char*)"bundle", "");
-       Agsym_t* eclrs = NULL;
+       Agsym_t* eclrs = nullptr;
        Agnode_t* n;
        Agedge_t* e;
        int i, j;
@@ -375,8 +375,8 @@ export_dot (FILE* fp, int ne, pedge *edges, Agraph_t* g)
 static int
 bundle (Agraph_t* g, opts_t* opts)
 {
-       double *x = NULL;
-       double *label_sizes = NULL;
+       double *x = nullptr;
+       double *label_sizes = nullptr;
        int n_edge_label_nodes;
        int dim = 2;
        SparseMatrix A;
@@ -393,12 +393,12 @@ bundle (Agraph_t* g, opts_t* opts)
                return 1;
        }
     initDotIO(g);
-       A = SparseMatrix_import_dot(g, dim, &label_sizes, &x, &n_edge_label_nodes, NULL, FORMAT_CSR, NULL);
+       A = SparseMatrix_import_dot(g, dim, &label_sizes, &x, &n_edge_label_nodes, nullptr, FORMAT_CSR, nullptr);
        if (!A){
                agerr (AGERR, "Error: could not convert graph %s (%s) into matrix\n", agnameof(g), fname);
                return 1;
     }
-    if (x == NULL) {
+    if (x == nullptr) {
                agerr (AGPREV, " in file %s\n",  fname);
                return 1;
     }
@@ -480,13 +480,13 @@ bundle (Agraph_t* g, opts_t* opts)
 
 static Agraph_t *gread(FILE * fp)
 {
-    return agread(fp, NULL);
+    return agread(fp, nullptr);
 }
 
 int main(int argc, char *argv[])
 {
        Agraph_t *g;
-       Agraph_t *prev = NULL;
+       Agraph_t *prev = nullptr;
        ingraph_state ig;
        int rv = 0;
        opts_t opts;