[multiple] avoid empty chunks in chunkqueue

(This might render some calls to chunkqueue_remove_finished_chunks()
 no longer necessary)

src/chunk.c

@@ -554,6 +554,8 @@ void chunkqueue_update_file(chunkqueue * const restrict cq, chunk *c, off_t len)
     /*assert(c->type == FILE_CHUNK);*/
     c->file.length += len;
     cq->bytes_in += len;
+    if (0 == chunk_remaining_length(c))
+        chunkqueue_remove_empty_chunks(cq);
 }
 
 void chunkqueue_set_tempdirs_default (const array *tempdirs, off_t upload_temp_file_size) {
@@ -764,6 +766,11 @@ int chunkqueue_append_mem_to_tempfile(chunkqueue * const restrict dest, const ch
 	}
 
 	do {
+		/*(aside: arg len is permitted to be 0 and creates tempfile as a
+		 * side effect.  This is used by mod_ssi for ssi exec, as the func
+		 * chunkqueue_get_append_tempfile() is not public.  The result is
+		 * an empty chunk at the end of the chunkqueue, which typically
+		 * should be avoided)*/
 		dst_c = chunkqueue_get_append_tempfile(dest, errh);
 		if (NULL == dst_c)
 			return -1;

src/mod_dirlisting.c

@@ -1185,9 +1185,10 @@ static void http_list_directory(request_st * const r, handler_ctx * const hctx)
 	}
 
 	if (out == tb) {
-		if (0 != chunkqueue_append_mem_to_tempfile(cq,
-		                                           BUF_PTR_LEN(out),
-		                                           r->conf.errh)) {
+		if (!buffer_is_blank(out)
+		    && 0 != chunkqueue_append_mem_to_tempfile(cq,
+		                                              BUF_PTR_LEN(out),
+		                                              r->conf.errh)) {
 			/* ignore */
 		}
 	}

src/mod_ssi.c

@@ -802,33 +802,30 @@ static int process_ssi_stmt(request_st * const r, handler_ctx * const p, const c
 		*(const char **)&args[2] = cmd;
 		args[3] = NULL;
 
+		int status = 0;
+		struct stat stb;
+		stb.st_size = 0;
 		/*(expects STDIN_FILENO open to /dev/null)*/
 		int serrh_fd = r->conf.serrh ? r->conf.serrh->fd : -1;
 		pid = fdevent_fork_execve(args[0], args, NULL, -1, c->file.fd, serrh_fd, -1);
 		if (-1 == pid) {
 			log_perror(errh, __FILE__, __LINE__, "spawning exec failed: %s", cmd);
+		} else if (fdevent_waitpid(pid, &status, 0) < 0) {
+			log_perror(errh, __FILE__, __LINE__, "waitpid failed");
 		} else {
-			struct stat stb;
-			int status = 0;
-
 			/* wait for the client to end */
 			/* NOTE: synchronous; blocks entire lighttpd server */
 
 			/*
 			 * OpenBSD and Solaris send a EINTR on SIGCHILD even if we ignore it
 			 */
-			if (fdevent_waitpid(pid, &status, 0) < 0) {
-				log_perror(errh, __FILE__, __LINE__, "waitpid failed");
-				break;
-			}
 			if (!WIFEXITED(status)) {
 				log_error(errh, __FILE__, __LINE__, "process exited abnormally: %s", cmd);
 			}
 			if (0 == fstat(c->file.fd, &stb)) {
-				chunkqueue_update_file(cq, c, stb.st_size);
 			}
 		}
-
+		chunkqueue_update_file(cq, c, stb.st_size);
 		break;
 	}
 	case SSI_IF: {