added a test case to exercise a bug in ngx_gunzip module with which ngx.flush(true) could hang forever. thanks Maxim Dounin for the catch. to make this test pass, we need the gzip_flush_bug patch applied to the nginx core.

Author: agentzh

t/056-flush.t

@@ -14,7 +14,7 @@ use t::TestNginxLua;
 
 repeat_each(2);
 
-plan tests => repeat_each() * 54;
+plan tests => repeat_each() * 55;
 
 #no_diff();
 no_long_string();
@@ -456,3 +456,34 @@ Content-Encoding: gzip
 --- no_error_log
 [error]
 
+
+
+=== TEST 16: flush wait - gunzip
+--- config
+    location /test {
+        gunzip on;
+        content_by_lua '
+            local f, err = io.open(ngx.var.document_root .. "/gzip.bin", "r")
+            if not f then
+                ngx.say("failed to open file: ", err)
+                return
+            end
+            local data = f:read(100)
+            ngx.header.content_encoding = "gzip"
+            ngx.print(data)
+            local ok, err = ngx.flush(true)
+            if not ok then
+                ngx.log(ngx.ERR, "flush failed: ", err)
+                return
+            end
+        ';
+    }
+--- user_files eval
+">>> gzip.bin
+\x1f\x8b\x08\x00\x00\x00\x00\x00\x02\x03\xb5\x19\xdb\x6e\x1b\xc7\xf5\x9d\x5f\x31\x5d\xa3\xa0\x84\x68\x2f\xbc\xc8\xb2\x28\x92\x85\x2d\x19\x8e\x01\x4b\x11\x6a\xa5\x69\x60\x18\xc2\x70\x77\xb8\x1c\x6b\xb9\xb3\x9e\x99\x25\xc5\x24\x06\x12\xe4\xa1\xcf\x45\x81\x16\x05\x8a\x3e\x14\x28\x5a\x04\x6d\x9f\xd3\xa2\x7d\xca\x0f\xd8\x4f\xfe\x81\xc0\xed\x67\xf4\x9c\xd9\x5d\x72\x79\x91\x25\x32\x91\x04\x51\x7b\xe6\x5c"
+--- request
+GET /test
+--- ignore_response
+--- no_error_log
+[error]
+

util/build2.sh

@@ -44,6 +44,7 @@ time ngx-build $force $version \
                 --add-module=$root/../rds-json-nginx-module \
                 --add-module=$root/../coolkit-nginx-module \
                 --add-module=$root/../redis2-nginx-module \
+                --with-http_gunzip_module \
           --with-select_module \
           --with-poll_module \
           --with-rtsig_module \