Found and fixed issue occuring when function was loaded from a module pretty couldn't find.

function.lua

@@ -181,9 +181,15 @@ local function get_function_body_info (info)
 	if info.defined_how == 'file' then
 		-- Read file
 		local file = io.open(info.short_src, 'r')
+		if file then
 			str = file:read '*all'
 			file:close()
+		else
+			str = nil
 		end
+	end
+
+	if not str then  return info  end
 
 	-- Calculate indices of the lines the function should be defined at.
     local start_line_index  =  get_line_index(str, info.linedefined)
@@ -255,10 +261,10 @@ return function (value, depth, l, format_value)
 
 	local function_params, function_body  =  nil, '...'
 
-	if not info.docs then
+	if not info.docs and info.defined_how ~= 'C' then
 		info = get_function_body_info(info)
 
-		if #info.body <= NR_CHARS_IN_LONG_FUNCTION_BODY and not info.body:find '\n' and not info.body:find(FUNCTION_KEYWORD_MATCH) then
+		if info.body and #info.body <= NR_CHARS_IN_LONG_FUNCTION_BODY and not info.body:find '\n' and not info.body:find(FUNCTION_KEYWORD_MATCH) then
 			if info.defined_how == 'string' then  function_body  =  info.body  end
 		end
 	end

test/test_pretty.lua

@@ -377,6 +377,29 @@ if HAS_JIT_LIBRARY then
     }
 end
 
+--------------------------------------------------------------------------------
+-- General
+
+SUITE:addTest('UseCase: Can print _G with max_depth = 1', function ()
+    format(_G, {max_depth = 1})
+    assert(true)
+end)
+
+SUITE:addTest('UseCase: Can load function from file that is shortly deleted', function ()
+    local module_name = 'tmp_'..os.time()
+    -- Create module
+    local file = io.open('./'..module_name..'.lua', 'w')
+          file:write '\nlocal function yo ()\n    -- Hello World\n    return math.random()\nend\n\nreturn yo\n'
+          file:close()
+    -- Load module
+    local yo = require(module_name)
+    -- Remove module
+    os.remove('./'..module_name..'.lua')
+    -- Format the function, even though the module it came from is gone.
+    format(yo)
+    assert(true)
+end)
+
 --------------------------------------------------------------------------------
 
 return SUITE