From c1a969ceddba3afd952ca8b6d3351b452481be6f Mon Sep 17 00:00:00 2001
From: Alex Hultman <alexhultman@gmail.com>
Date: Mon, 20 Apr 2020 00:12:56 +0200
Subject: [PATCH] Fix router in regards to empty url segments

---
 src/HttpRouter.h     | 40 +++++++++++++++++++++++++---------------
 tests/HttpRouter.cpp | 38 ++++++++++++++++++++++++++++++++++++--
 2 files changed, 61 insertions(+), 17 deletions(-)

diff --git a/src/HttpRouter.h b/src/HttpRouter.h
index dd62269..7c61698 100644
--- a/src/HttpRouter.h
+++ b/src/HttpRouter.h
@@ -25,6 +25,7 @@
 #include <string>
 #include <algorithm>
 #include <memory>
+#include <utility>
 
 #include "f2/function2.hpp"
 
@@ -107,19 +108,25 @@ private:
 
     /* Set URL for router. Will reset any URL cache */
     inline void setUrl(std::string_view url) {
-        /* Remove / from input URL */
-        currentUrl = url.substr(std::min<unsigned int>((unsigned int) url.length(), 1));
+
+        /* Todo: URL may also start with "http://domain/" or "*", not only "/" */
+
+        /* We expect to stand on a slash */
+        currentUrl = url;
         urlSegmentTop = -1;
     }
 
     /* Lazily parse or read from cache */
-    inline std::string_view getUrlSegment(int urlSegment) {
+    inline std::pair<std::string_view, bool> getUrlSegment(int urlSegment) {
         if (urlSegment > urlSegmentTop) {
-            /* Return empty segment if we are out of URL or stack space, but never for first url segment */
+            /* Signal as STOP when we have no more URL or stack space */
             if (!currentUrl.length() || urlSegment > 99) {
-                return {};
+                return {{}, true};
             }
 
+            /* We always stand on a slash here, so step over it */
+            currentUrl.remove_prefix(1);
+
             auto segmentLength = currentUrl.find('/');
             if (segmentLength == std::string::npos) {
                 segmentLength = currentUrl.length();
@@ -136,17 +143,20 @@ private:
                 urlSegmentTop++;
 
                 /* Update currentUrl */
-                currentUrl = currentUrl.substr(segmentLength + 1);
+                currentUrl = currentUrl.substr(segmentLength);
             }
         }
         /* In any case we return it */
-        return urlSegmentVector[urlSegment];
+        return {urlSegmentVector[urlSegment], false};
     }
 
     /* Executes as many handlers it can */
     bool executeHandlers(Node *parent, int urlSegment, USERDATA &userData) {
-        /* If we have no more URL and not on first round, return where we may stand */
-        if (urlSegment && !getUrlSegment(urlSegment).length()) {
+
+        auto [segment, isStop] = getUrlSegment(urlSegment);
+
+        /* If we are on STOP, return where we may stand */
+        if (isStop) {
             /* We have reached accross the entire URL with no stoppage, execute */
             for (int handler : parent->handlers) {
                 if (handlers[handler & HANDLER_MASK](this)) {
@@ -165,14 +175,14 @@ private:
                         return true;
                     }
                 }
-            } else if (p->name.length() && p->name[0] == ':' && getUrlSegment(urlSegment).length()) {
+            } else if (p->name.length() && p->name[0] == ':' && segment.length()) {
                 /* Parameter match */
-                routeParameters.push(getUrlSegment(urlSegment));
+                routeParameters.push(segment);
                 if (executeHandlers(p.get(), urlSegment + 1, userData)) {
                     return true;
                 }
                 routeParameters.pop();
-            } else if (p->name == getUrlSegment(urlSegment)) {
+            } else if (p->name == segment) {
                 /* Static match */
                 if (executeHandlers(p.get(), urlSegment + 1, userData)) {
                     return true;
@@ -223,8 +233,8 @@ public:
             Node *node = getNode(&root, method, false);
             /* Iterate over all segments */
             setUrl(pattern);
-            for (int i = 0; getUrlSegment(i).length() || i == 0; i++) {
-                node = getNode(node, std::string(getUrlSegment(i)), priority == HIGH_PRIORITY);
+            for (int i = 0; !getUrlSegment(i).second; i++) {
+                node = getNode(node, std::string(getUrlSegment(i).first), priority == HIGH_PRIORITY);
             }
             /* Insert handler in order sorted by priority (most significant 1 byte) */
             node->handlers.insert(std::upper_bound(node->handlers.begin(), node->handlers.end(), (uint32_t) (priority | handlers.size())), (uint32_t) (priority | handlers.size()));
@@ -237,4 +247,4 @@ public:
 
 }
 
-#endif // UWS_HTTPROUTER_HPP
\ No newline at end of file
+#endif // UWS_HTTPROUTER_HPP
diff --git a/tests/HttpRouter.cpp b/tests/HttpRouter.cpp
index 61dbda8..3ab2e7c 100644
--- a/tests/HttpRouter.cpp
+++ b/tests/HttpRouter.cpp
@@ -128,6 +128,40 @@ void testUpgrade() {
 
 void testBugReports() {
     std::cout << "TestBugReports" << std::endl;
+    {
+        uWS::HttpRouter<int> r;
+        std::string result;
+
+        r.add({"get"}, "/foo//////bar/baz/qux", [&result](auto *) {
+            result += "MANYSLASH";
+            return false;
+        }, r.MEDIUM_PRIORITY);
+
+        r.add({"get"}, "/foo", [&result](auto *) {
+            result += "FOO";
+            return false;
+        }, r.MEDIUM_PRIORITY);
+
+        r.route("get", "/foo");
+        r.route("get", "/foo/");
+        r.route("get", "/foo//bar/baz/qux");
+        r.route("get", "/foo//////bar/baz/qux");
+        assert(result == "FOOMANYSLASH");
+    }
+
+    {
+        uWS::HttpRouter<int> r;
+        std::string result;
+
+        r.add({"get"}, "/test/*", [&result](auto *) {
+            result += "TEST";
+            return false;
+        }, r.MEDIUM_PRIORITY);
+
+        r.route("get", "/test/");
+        assert(result == "TEST");
+    }
+
     {
         uWS::HttpRouter<int> r;
         std::string result;
@@ -293,7 +327,7 @@ void testParameters() {
     r.route("get", "/candy/lollipop/");
     r.route("get", "/candy/lollipop");
     r.route("get", "/candy/");
-    assert(result == "");
+    assert(result == "GLWGPW");
 }
 
 int main() {
@@ -302,4 +336,4 @@ int main() {
     testUpgrade();
     testBugReports();
     testParameters();
-}
\ No newline at end of file
+}