Further request method check strengthening.

* Encountering them returns an error, `HPE_INVALID_METHOD`
* Tests have been added.

http_parser.c

@@ -936,6 +936,7 @@ size_t http_parser_execute (http_parser *parser,
           } else if (parser->index == 2  && ch == 'P') {
             parser->method = HTTP_COPY;
           } else {
+            SET_ERRNO(HPE_INVALID_METHOD);
             goto error;
           }
         } else if (parser->method == HTTP_MKCOL) {
@@ -948,12 +949,14 @@ size_t http_parser_execute (http_parser *parser,
           } else if (parser->index == 2 && ch == 'A') {
             parser->method = HTTP_MKACTIVITY;
           } else {
+            SET_ERRNO(HPE_INVALID_METHOD);
             goto error;
           }
         } else if (parser->method == HTTP_SUBSCRIBE) {
           if (parser->index == 1 && ch == 'E') {
             parser->method = HTTP_SEARCH;
           } else {
+            SET_ERRNO(HPE_INVALID_METHOD);
             goto error;
           }
         } else if (parser->index == 1 && parser->method == HTTP_POST) {
@@ -964,13 +967,27 @@ size_t http_parser_execute (http_parser *parser,
           } else if (ch == 'A') {
             parser->method = HTTP_PATCH;
           } else {
+            SET_ERRNO(HPE_INVALID_METHOD);
             goto error;
           }
         } else if (parser->index == 2) {
           if (parser->method == HTTP_PUT) {
-            if (ch == 'R') parser->method = HTTP_PURGE;
+            if (ch == 'R') {
+              parser->method = HTTP_PURGE;
+            } else {
+              SET_ERRNO(HPE_INVALID_METHOD);
+              goto error;
+            }
           } else if (parser->method == HTTP_UNLOCK) {
-            if (ch == 'S') parser->method = HTTP_UNSUBSCRIBE;
+            if (ch == 'S') {
+              parser->method = HTTP_UNSUBSCRIBE;
+            } else {
+              SET_ERRNO(HPE_INVALID_METHOD);
+              goto error;
+            }
+          } else {
+            SET_ERRNO(HPE_INVALID_METHOD);
+            goto error;
           }
         } else if (parser->index == 4 && parser->method == HTTP_PROPFIND && ch == 'P') {
           parser->method = HTTP_PROPPATCH;

test.c

@@ -3117,14 +3117,8 @@ main (void)
 
   /// REQUESTS
 
-  test_simple("hello world", HPE_INVALID_METHOD);
   test_simple("GET / HTP/1.1\r\n\r\n", HPE_INVALID_VERSION);
 
-
-  test_simple("ASDF / HTTP/1.1\r\n\r\n", HPE_INVALID_METHOD);
-  test_simple("PROPPATCHA / HTTP/1.1\r\n\r\n", HPE_INVALID_METHOD);
-  test_simple("GETA / HTTP/1.1\r\n\r\n", HPE_INVALID_METHOD);
-
   // Well-formed but incomplete
   test_simple("GET / HTTP/1.1\r\n"
               "Content-Type: text/plain\r\n"
@@ -3167,13 +3161,23 @@ main (void)
   }
 
   static const char *bad_methods[] = {
+      "ASDF",
       "C******",
+      "COLA",
+      "GEM",
+      "GETA",
       "M****",
+      "MKCOLA",
+      "PROPPATCHA",
+      "PUN",
+      "PX",
+      "SA",
+      "hello world",
       0 };
   for (this_method = bad_methods; *this_method; this_method++) {
     char buf[200];
     sprintf(buf, "%s / HTTP/1.1\r\n\r\n", *this_method);
-    test_simple(buf, HPE_UNKNOWN);
+    test_simple(buf, HPE_INVALID_METHOD);
   }
 
   const char *dumbfuck2 =