use a stronger type for root variable

diff --git a/lib/cgraph/write.c b/lib/cgraph/write.c
index 5735ee9a8fd12f2ca70e7f96b259d810d23036db..150ea824cb9fddf5f4c3d479174a78b49365c299 100644 (file)
--- a/lib/cgraph/write.c
+++ b/lib/cgraph/write.c
@@ -282,7 +282,7 @@ static int write_dicts(Agraph_t * g, iochan_t * ofile, int top)
 static int write_hdr(Agraph_t * g, iochan_t * ofile, int top)
 {
     char *name, *sep, *kind, *strict;
-    int root = 0;
+    bool root = false;
     bool hasName = true;
 
     Attrs_not_written_flag = AGATTRWF(g);
@@ -290,7 +290,7 @@ static int write_hdr(Agraph_t * g, iochan_t * ofile, int top)
     if (NOT(top) && agparent(g))
        kind = "sub";
     else {
-       root = 1;
+       root = true;
        if (g->desc.directed)
            kind = "di";
        else