Define CMARK_OPT_SAFE for API compatibility.

It doesn't do anything; this is documented.

Author: jgm

man/man3/cmark.3

@@ -1,4 +1,4 @@
-.TH cmark 3 "March 17, 2019" "LOCAL" "Library Functions Manual"
+.TH cmark 3 "March 19, 2019" "LOCAL" "Library Functions Manual"
 .SH
 NAME
 .PP
@@ -717,6 +717,20 @@ Include a \f[C]data\-sourcepos\f[] attribute on all block elements.
 .PP
 Render \f[C]softbreak\f[] elements as hard line breaks.
 
+.PP
+.nf
+\fC
+.RS 0n
+#define CMARK_OPT_SAFE (1 << 3)
+.RE
+\f[]
+.fi
+
+.PP
+\f[C]CMARK_OPT_SAFE\f[] is defined here for API compatibility, but it no
+longer has any effect. "Safe" mode is now the default: set
+\f[C]CMARK_OPT_UNSAFE\f[] to disable it.
+
 .PP
 .nf
 \fC

src/cmark.h

@@ -552,6 +552,12 @@ char *cmark_render_latex(cmark_node *root, int options, int width);
  */
 #define CMARK_OPT_HARDBREAKS (1 << 2)
 
+/** `CMARK_OPT_SAFE` is defined here for API compatibility,
+    but it no longer has any effect. "Safe" mode is now the default:
+    set `CMARK_OPT_UNSAFE` to disable it.
+ */
+#define CMARK_OPT_SAFE (1 << 3)
+
 /** Render raw HTML and unsafe links (`javascript:`, `vbscript:`,
  * `file:`, and `data:`, except for `image/png`, `image/gif`,
  * `image/jpeg`, or `image/webp` mime types).  By default,