Merge pull request #1275 from pjhades/fix/escript

Allow escripts with only two lines

OTP-14098

3 files changed, 59 insertions, 41 deletions

diff --git a/lib/stdlib/src/escript.erl b/lib/stdlib/src/escript.erl
index 7f5ef4df42..c42ae981e7 100644
--- a/lib/stdlib/src/escript.erl
+++ b/lib/stdlib/src/escript.erl
@@ -481,46 +481,49 @@ find_first_body_line(Fd, HeaderSz0, LineNo, KeepFirst, Sections) ->
     %% Look for special comment on second line
     Line2 = get_line(Fd),
     {ok, HeaderSz2} = file:position(Fd, cur),
-    case classify_line(Line2) of
-	emu_args ->
-	    %% Skip special comment on second line
-	    Line3 = get_line(Fd),
-	    {HeaderSz2, LineNo + 2, Fd,
-	     Sections#sections{type = guess_type(Line3),
-			       comment = undefined,
-			       emu_args = Line2}};
-	Line2Type ->
-	    %% Look for special comment on third line
-	    Line3 = get_line(Fd),
-	    {ok, HeaderSz3} = file:position(Fd, cur),
-	    Line3Type = classify_line(Line3),
-	    if
-		Line3Type =:= emu_args ->
-		    %% Skip special comment on third line
-		    Line4 = get_line(Fd),
-		    {HeaderSz3, LineNo + 3, Fd,
-		     Sections#sections{type = guess_type(Line4),
-				       comment = Line2,
-				       emu_args = Line3}};
-		Sections#sections.shebang =:= undefined,
-		KeepFirst =:= true ->
-		    %% No shebang. Use the entire file
-		    {HeaderSz0, LineNo, Fd,
-		     Sections#sections{type = guess_type(Line2)}};
-		Sections#sections.shebang =:= undefined ->
-		    %% No shebang. Skip the first line
-		    {HeaderSz1, LineNo, Fd,
-		     Sections#sections{type = guess_type(Line2)}};
-		Line2Type =:= comment ->
-		    %% Skip shebang on first line and comment on second
-		    {HeaderSz2, LineNo + 2, Fd,
-		     Sections#sections{type = guess_type(Line3),
-				       comment = Line2}};
-		true ->
-		    %% Just skip shebang on first line
-		    {HeaderSz1, LineNo + 1, Fd,
-		     Sections#sections{type = guess_type(Line2)}}
-	    end
+    if
+        Sections#sections.shebang =:= undefined,
+        KeepFirst =:= true ->
+            %% No shebang. Use the entire file
+            {HeaderSz0, LineNo, Fd,
+             Sections#sections{type = guess_type(Line2)}};
+        Sections#sections.shebang =:= undefined ->
+            %% No shebang. Skip the first line
+            {HeaderSz1, LineNo, Fd,
+             Sections#sections{type = guess_type(Line2)}};
+        true ->
+            case classify_line(Line2) of
+                emu_args ->
+                    %% Skip special comment on second line
+                    Line3 = get_line(Fd),
+                    {HeaderSz2, LineNo + 2, Fd,
+                     Sections#sections{type = guess_type(Line3),
+                                       comment = undefined,
+                                       emu_args = Line2}};
+                comment ->
+                    %% Look for special comment on third line
+                    Line3 = get_line(Fd),
+                    {ok, HeaderSz3} = file:position(Fd, cur),
+                    Line3Type = classify_line(Line3),
+                    if
+                        Line3Type =:= emu_args ->
+                            %% Skip special comment on third line
+                            Line4 = get_line(Fd),
+                            {HeaderSz3, LineNo + 3, Fd,
+                             Sections#sections{type = guess_type(Line4),
+                                               comment = Line2,
+                                               emu_args = Line3}};
+                        true ->
+                            %% Skip shebang on first line and comment on second
+                            {HeaderSz2, LineNo + 2, Fd,
+                             Sections#sections{type = guess_type(Line3),
+                                               comment = Line2}}
+                    end;
+                _ ->
+                    %% Just skip shebang on first line
+                    {HeaderSz1, LineNo + 1, Fd,
+                     Sections#sections{type = guess_type(Line2)}}
+            end
     end.
 
 classify_line(Line) ->
diff --git a/lib/stdlib/test/escript_SUITE.erl b/lib/stdlib/test/escript_SUITE.erl
index 28d69232a0..0b9106a99c 100644
--- a/lib/stdlib/test/escript_SUITE.erl
+++ b/lib/stdlib/test/escript_SUITE.erl
@@ -28,6 +28,7 @@
 	 strange_name/1,
 	 emulator_flags/1,
 	 emulator_flags_no_shebang/1,
+	 two_lines/1,
 	 module_script/1,
 	 beam_script/1,
 	 archive_script/1,
@@ -49,7 +50,7 @@ suite() ->
 
 all() -> 
     [basic, errors, strange_name, emulator_flags,
-     emulator_flags_no_shebang,
+     emulator_flags_no_shebang, two_lines,
      module_script, beam_script, archive_script, epp,
      create_and_extract, foldl, overflow,
      archive_script_file_access, unicode].
@@ -153,6 +154,18 @@ emulator_flags(Config) when is_list(Config) ->
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
+two_lines(Config) when is_list(Config) ->
+    Data = proplists:get_value(data_dir, Config),
+    Dir = filename:absname(Data),		%Get rid of trailing slash.
+    run(Dir, "two_lines -arg1 arg2 arg3",
+	[<<"main:[\"-arg1\",\"arg2\",\"arg3\"]\n"
+	   "ERL_FLAGS=false\n"
+	   "unknown:[]\n"
+	   "ExitCode:0">>]),
+    ok.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
 emulator_flags_no_shebang(Config) when is_list(Config) ->
     Data = proplists:get_value(data_dir, Config),
     Dir = filename:absname(Data),		%Get rid of trailing slash.
diff --git a/lib/stdlib/test/escript_SUITE_data/two_lines b/lib/stdlib/test/escript_SUITE_data/two_lines
new file mode 100755
index 0000000000..cf4e99639c
--- /dev/null
+++ b/lib/stdlib/test/escript_SUITE_data/two_lines
@@ -0,0 +1,2 @@
+#! /usr/bin/env escript
+main(MainArgs) -> io:format("main:~p\n", [MainArgs]), ErlArgs = init:get_arguments(), io:format("ERL_FLAGS=~p\n", [os:getenv("ERL_FLAGS")]), io:format("unknown:~p\n",[[E || E <- ErlArgs, element(1, E) =:= unknown]]).