Add getHeaderValue predicate to HTTP::HeaderWrite

ql/src/semmle/go/concepts/HTTP.qll

@@ -64,10 +64,17 @@ module HTTP {
       /** Gets the (lower-case) name of a header set by this definition. */
       string getHeaderName() { result = this.getName().getStringValue().toLowerCase() }
 
+      /** Gets the value of the header set by this definition. */
+      string getHeaderValue() {
+        result = this.getValue().getStringValue()
+        or
+        result = this.getValue().getIntValue().toString()
+      }
+
       /** Holds if this header write defines the header `header`. */
       predicate definesHeader(string header, string value) {
         header = this.getHeaderName() and
-        value = this.getValue().getStringValue()
+        value = this.getHeaderValue()
       }
 
       /**
@@ -101,6 +108,9 @@ module HTTP {
     /** Gets the (lower-case) name of a header set by this definition. */
     string getHeaderName() { result = self.getHeaderName() }
 
+    /** Gets the value of the header set by this definition. */
+    string getHeaderValue() { result = self.getHeaderValue() }
+
     /** Holds if this header write defines the header `header`. */
     predicate definesHeader(string header, string value) { self.definesHeader(header, value) }
 

ql/src/semmle/go/frameworks/stdlib/NetHttp.qll

@@ -108,9 +108,7 @@ module NetHttp {
 
     override string getHeaderName() { result = "status" }
 
-    override predicate definesHeader(string header, string value) {
-      header = "status" and value = this.getValue().getIntValue().toString()
-    }
+    override string getHeaderValue() { result = this.getValue().getIntValue().toString() }
 
     override DataFlow::Node getName() { none() }
 

ql/test/library-tests/semmle/go/concepts/HTTP/main.go

@@ -3,9 +3,9 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"html"
 	"io"
 	"io/ioutil"
-	"net/html"
 	"net/http"
 )