take a const pointer as the first argument to agcanonhtmlstr

This function does not modify its string argument, so it is more accurate to
qualify it as const. Related to #634.

diff --git a/lib/cgraph/write.c b/lib/cgraph/write.c
index a23c5e715606fee01d7a73b2658c52b59615068a..9515ab5efd0ff1d49c9a220d8cb5ce3b707e6a32 100644 (file)
--- a/lib/cgraph/write.c
+++ b/lib/cgraph/write.c
@@ -139,7 +139,7 @@ static char *_agstrcanon(char *arg, char *buf)
 /* agcanonhtmlstr:
  * Canonicalize html strings. 
  */
-static char *agcanonhtmlstr(char *arg, char *buf)
+static char *agcanonhtmlstr(const char *arg, char *buf)
 {
     sprintf(buf, "<%s>", arg);
     return buf;