Replaced HTTP response zero-termination with explicit length.

If we want to be able to send application/octet-stream we can't rely on the HTTP response to not contain a zero byte.

ip65/httpd.s

@@ -14,6 +14,7 @@ HTTPD_TIMEOUT_SECONDS = 5       ; what's the maximum time we let 1 connection be
 .export httpd_start
 .export httpd_port_number
 .export httpd_send_response
+.export httpd_response_buffer_length
 
 .import http_parse_request
 .import tcp_listen
@@ -40,6 +41,7 @@ temp_ptr = ptr1
 io_buf:                         .res $800
 found_eol:                      .res 1
 connection_closed:              .res 1
+httpd_response_buffer_length:   .res 2
 output_buffer_length:           .res 2
 sent_header:                    .res 1
 connection_timeout_seconds:     .res 1
@@ -213,6 +215,7 @@ reset_output_buffer:
 ; send HTTP response
 ; inputs:
 ; AX = pointer to data to be sent
+; httpd_response_buffer_length = length of data to be sent
 ; Y = content type/status code
 ; outputs:
 ; none
@@ -222,12 +225,17 @@ httpd_send_response:
   jsr send_header
 
 @response_loop:
-  jsr get_next_byte
+  dec httpd_response_buffer_length
-  cmp #0
+  lda httpd_response_buffer_length
+  cmp #$ff
+  bne @not_last_byte
+  dec httpd_response_buffer_length+1
+  lda httpd_response_buffer_length+1
+  cmp #$ff
   bne @not_last_byte
-@send_buffer:
   jmp send_buffer
 @not_last_byte:
+  jsr get_next_byte
   jsr emit_a
   jmp @response_loop
 

test/httpd.s

@@ -2,11 +2,14 @@
 .include "../inc/commonprint.i"
 .include "../inc/net.i"
 
+.define HTML "<h1>Hello World</h1><form>Your Name: <input name=n type=text length=20><br>Your Message: <input name=m type=text lengh=60><br><input type=submit></form>"
+
 .export start
 
 .import exit_to_basic
 
 .import httpd_start
+.import httpd_response_buffer_length
 .import http_get_value
 
 
@@ -50,6 +53,9 @@ print_vars:
 
 httpd_callback:
   jsr print_vars
+  lda #<.strlen(HTML)
+  ldx #>.strlen(HTML)
+  stax httpd_response_buffer_length
   ldax #html
   ldy #2                        ; text/html
   clc
@@ -65,7 +71,7 @@ listening:
 said:
   .byte " said ",0
 html:
-  .byte "<h1>Hello World</h1><form>Your Name: <input name=n type=text length=20><br>Your Message: <input name=m type=text lengh=60><br><input type=submit></form>",0
+  .byte HTML