Fix. Progress function should return 1 to continue.

doc/lcurl.ldoc

@@ -329,8 +329,11 @@ function setopt_readfunction() end
 -- the third is the number of bytes downloaded so far,
 -- the fourth is the total number of bytes expected to be uploaded
 -- in this transfer, and the fifth is the number of bytes uploaded so far.
--- Function must return `true` or or nothing to continue operation.
--- Otherwise the transfer will be aborted with an error.
+-- Function must return `true` or `1` or nothing to continue operation.
+-- Otherwise the transfer will be aborted with an error `ABORTED_BY_CALLBACK`.<br/>
+--
+-- !!! NOTE !!! This is differents form libcurl API. In libcurl returning a non-zero 
+-- value from this callback will cause libcurl to abort the transfer and return.
 --
 -- @tparam function progress
 -- @param[opt] context progress context

src/lceasy.c

@@ -785,7 +785,10 @@ static int lcurl_xferinfo_callback(void *arg, curl_off_t dltotal, curl_off_t dln
     }
     if(lua_isboolean(L, top + 1))
       ret = lua_toboolean(L, top + 1)?0:1;
-    else ret = (size_t)lua_tonumber(L, top + 1);
+    else{
+      ret = (size_t)lua_tonumber(L, top + 1);
+      if(ret == 0) ret = 1; else ret = 0;
+    }
   }
 
   lua_settop(L, top);

test/test_easy.lua

@@ -114,6 +114,115 @@ function test_write_pass_03()
 end
 
 
+end
+
+local _ENV = TEST_CASE'progress_callback' do
+
+local c
+
+local function pass() end
+
+function teardown()
+  if f then f:close() end
+  os.remove(fname)
+  if c then c:close() end
+  f, c = nil
+end
+
+function test_abort_01()
+  c  = assert(scurl.easy{
+    url              = url,
+    writefunction    = pass,
+    noprogress       = false,
+    progressfunction = function() return false end
+  })
+
+  local _, e = assert_nil(c:perform())
+  assert_equal(curl.error(curl.ERROR_EASY, curl.E_ABORTED_BY_CALLBACK), e)
+end
+
+function test_abort_02()
+  c  = assert(scurl.easy{
+    url              = url,
+    writefunction    = pass,
+    noprogress       = false,
+    progressfunction = function() return 0 end
+  })
+
+  local _, e = assert_nil(c:perform())
+  assert_equal(curl.error(curl.ERROR_EASY, curl.E_ABORTED_BY_CALLBACK), e)
+end
+
+function test_abort_03()
+  c  = assert(scurl.easy{
+    url              = url,
+    writefunction    = pass,
+    noprogress       = false,
+    progressfunction = function() return nil end
+  })
+
+  local _, e = assert_nil(c:perform())
+  assert_equal(curl.error(curl.ERROR_EASY, curl.E_ABORTED_BY_CALLBACK), e)
+end
+
+function test_abort_04()
+  c  = assert(scurl.easy{
+    url              = url,
+    writefunction    = pass,
+    noprogress       = false,
+    progressfunction = function() return nil, "PROGRESSERROR" end
+  })
+
+  local _, e = assert_nil(c:perform())
+  assert_equal("PROGRESSERROR", e)
+end
+
+function test_abort_05()
+  c  = assert(scurl.easy{
+    url              = url,
+    writefunction    = pass,
+    noprogress       = false,
+    progressfunction = function() error( "PROGRESSERROR" )end
+  })
+
+  assert_error_match("PROGRESSERROR", function()
+    c:perform()
+  end)
+end
+
+function test_pass_01()
+  c  = assert(scurl.easy{
+    url              = url,
+    writefunction    = pass,
+    noprogress       = false,
+    progressfunction = function() end
+  })
+
+  assert_equal(c, c:perform())
+end
+
+function test_pass_02()
+  c  = assert(scurl.easy{
+    url              = url,
+    writefunction    = pass,
+    noprogress       = false,
+    progressfunction = function() return true end
+  })
+
+  assert_equal(c, c:perform())
+end
+
+function test_pass_03()
+  c  = assert(scurl.easy{
+    url              = url,
+    writefunction    = pass,
+    noprogress       = false,
+    progressfunction = function() return 1 end
+  })
+
+  assert_equal(c, c:perform())
+end
+
 end
 
 local _ENV = TEST_CASE'escape' do