Escape diff strings in graphviz

Author: ashivaram23

compiler/rustc_mir_dataflow/src/framework/graphviz.rs

@@ -605,10 +605,10 @@ where
 
             self.write_row(w, &index_str, &statement_str, |_this, w, fmt| {
                 if let Some(before) = before {
-                    write!(w, r#"<td {fmt} align="left">{before}</td>"#)?;
+                    write!(w, r#"<td {fmt} align="left">{}</td>"#, dot::escape_html(&before))?;
                 }
 
-                write!(w, r#"<td {fmt} align="left">{after}</td>"#)
+                write!(w, r#"<td {fmt} align="left">{}</td>"#, dot::escape_html(&after))
             })?;
         }
 
@@ -624,10 +624,10 @@ where
 
         self.write_row(w, "T", &terminator_str, |_this, w, fmt| {
             if let Some(before) = before {
-                write!(w, r#"<td {fmt} align="left">{before}</td>"#)?;
+                write!(w, r#"<td {fmt} align="left">{}</td>"#, dot::escape_html(&before))?;
             }
 
-            write!(w, r#"<td {fmt} align="left">{after}</td>"#)
+            write!(w, r#"<td {fmt} align="left">{}</td>"#, dot::escape_html(&after))
         })
     }