HTTP pipelining: Fix handling of zero-length responses

Also add test case 584 for the same

Bug: http://curl.haxx.se/bug/view.cgi?id=3214223

lib/transfer.c

@@ -500,9 +500,28 @@ static CURLcode readwrite_data(struct SessionHandle *data,
       }
 #endif
 
-      if(stop_reading)
+      if(stop_reading) {
         /* We've stopped dealing with input, get out of the do-while loop */
-        break;
+
+        if(nread > 0) {
+          if(conn->data->multi && Curl_multi_canPipeline(conn->data->multi)) {
+            infof(data,
+                  "Rewinding stream by : %zd"
+                  " bytes on url %s (zero-length body)\n",
+                  nread, data->state.path);
+	    read_rewind(conn, (size_t)nread);
+          }
+	  else {
+            infof(data,
+                  "Excess found in a non pipelined read:"
+                  " excess = %zd"
+		  " url = %s (zero-length body)\n",
+                  nread, data->state.path);
+	  }
+	}
+
+	break;
+      }
     }
 #endif /* CURL_DISABLE_HTTP */
 

tests/data/Makefile.am

@@ -71,7 +71,7 @@ EXTRA_DIST = test1 test108 test117 test127 test20 test27 test34 test46	   \
  test1203 test1117 test1118 test1119 test1120 test1300 test1301 test1302 \
  test1303 test320 test321 test322 test323 test324 test1121 test581 test580 \
  test1304 test1305 test1306 test1307 test582 test583 test808 test809       \
- test810 test811 test812 test813
+ test810 test811 test812 test813 test584
 
 filecheck:
 	@mkdir test-place; \

tests/data/test584

@@ -0,0 +1,102 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+Pipelining
+multi
+</keywords>
+</info>
+
+# Server-side
+# Silly division of the first request is solely to appease the server which expects n_data_items == n_requests
+<reply>
+<data1>
+HTTP/1.1 200 OK
+Server: test-server/fake
+Content-Length: 4
+
+584
+</data1>
+<data2>
+HTTP/1.1 200 OK
+</data2>
+<data3>
+Server: test-server/fake
+</data3>
+<data4>
+Content-Length: 0
+
+HTTP/1.1 200 OK
+Server: test-server/fake
+Content-Length: 5
+
+585
+
+HTTP/1.1 200 OK
+Server: test-server/fake
+Content-Length: 4
+
+586
+</data4>
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+<tool>
+lib530
+</tool>
+ <name>
+HTTP GET using pipelining (nonzero length after zero length)
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/path/584
+</command>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+<protocol>
+GET /path/5840001 HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+Accept: */*
+
+GET /path/5840002 HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+Accept: */*
+
+GET /path/5840003 HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+Accept: */*
+
+GET /path/5840004 HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+Accept: */*
+
+</protocol>
+<stdout>
+HTTP/1.1 200 OK
+Server: test-server/fake
+Content-Length: 4
+
+584
+HTTP/1.1 200 OK
+Server: test-server/fake
+Content-Length: 0
+
+HTTP/1.1 200 OK
+Server: test-server/fake
+Content-Length: 5
+
+585
+
+HTTP/1.1 200 OK
+Server: test-server/fake
+Content-Length: 4
+
+586
+</stdout>
+</verify>
+</testcase>