File 2662-Only-allow-single-separator-between-digits.patch of Package erlang

From 3fd74ac49fad11ed9e4f78932b36aec44d2d6514 Mon Sep 17 00:00:00 2001
From: Sergey Prokhorov <seriy.pr@gmail.com>
Date: Fri, 19 Jul 2019 01:52:15 +0200
Subject: [PATCH 2/8] Only allow (single) separator between digits

---
 lib/stdlib/src/erl_scan.erl | 48 +++++++++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 21 deletions(-)

diff --git a/lib/stdlib/src/erl_scan.erl b/lib/stdlib/src/erl_scan.erl
index 4e5a51ae07..35ac83eb13 100644
--- a/lib/stdlib/src/erl_scan.erl
+++ b/lib/stdlib/src/erl_scan.erl
@@ -249,7 +249,7 @@ string_thing(_) -> "string".
 -define(WHITE_SPACE(C),
         is_integer(C) andalso
          (C >= $\000 andalso C =< $\s orelse C >= $\200 andalso C =< $\240)).
--define(DIGIT(C), C >= $0, C =< $9).
+-define(DIGIT(C), C >= $0 andalso C =< $9).
 -define(CHAR(C), is_integer(C), C >= 0).
 -define(UNICODE(C),
         is_integer(C) andalso
@@ -940,15 +940,16 @@ escape_char(C) -> C.
 
 scan_number([C|Cs], St, Line, Col, Toks, Ncs) when ?DIGIT(C) ->
     scan_number(Cs, St, Line, Col, Toks, [C|Ncs]);
-scan_number([$_|Cs], St, Line, Col, Toks, Ncs) ->
-    scan_number(Cs, St, Line, Col, Toks, Ncs);
+scan_number([$_,Next|Cs], St, Line, Col, Toks, [Prev|_]=Ncs) when
+      ?DIGIT(Next) andalso ?DIGIT(Prev) ->
+    scan_number(Cs, St, Line, Col, Toks, [Next,$_|Ncs]);
 scan_number([$.,C|Cs], St, Line, Col, Toks, Ncs) when ?DIGIT(C) ->
     scan_fraction(Cs, St, Line, Col, Toks, [C,$.|Ncs]);
 scan_number([$.]=Cs, _St, Line, Col, Toks, Ncs) ->
     {more,{Cs,Col,Toks,Line,Ncs,fun scan_number/6}};
 scan_number([$#|Cs]=Cs0, St, Line, Col, Toks, Ncs0) ->
     Ncs = lists:reverse(Ncs0),
-    case catch list_to_integer(Ncs) of
+    case catch list_to_integer(remove_digit_separators(Ncs)) of
         B when B >= 2, B =< 1+$Z-$A+10 ->
             Bcs = Ncs++[$#],
             scan_based_int(Cs, St, Line, Col, Toks, {B,[],Bcs});
@@ -960,7 +961,7 @@ scan_number([]=Cs, _St, Line, Col, Toks, Ncs) ->
     {more,{Cs,Col,Toks,Line,Ncs,fun scan_number/6}};
 scan_number(Cs, St, Line, Col, Toks, Ncs0) ->
     Ncs = lists:reverse(Ncs0),
-    case catch list_to_integer(Ncs) of
+    case catch list_to_integer(remove_digit_separators(Ncs)) of
         N when is_integer(N) ->
             tok3(Cs, St, Line, Col, Toks, integer, Ncs, N);
         _ ->
@@ -968,22 +969,25 @@ scan_number(Cs, St, Line, Col, Toks, Ncs0) ->
             scan_error({illegal,integer}, Line, Col, Line, Ncol, Cs)
     end.
 
-scan_based_int([C|Cs], St, Line, Col, Toks, {B,Ncs,Bcs})
-    when ?DIGIT(C), C < $0+B ->
-    scan_based_int(Cs, St, Line, Col, Toks, {B,[C|Ncs],Bcs});
-scan_based_int([C|Cs], St, Line, Col, Toks, {B,Ncs,Bcs})
-    when C >= $A, B > 10, C < $A+B-10 ->
-    scan_based_int(Cs, St, Line, Col, Toks, {B,[C|Ncs],Bcs});
-scan_based_int([C|Cs], St, Line, Col, Toks, {B,Ncs,Bcs})
-    when C >= $a, B > 10, C < $a+B-10 ->
+remove_digit_separators(Number) ->
+    [C || C <- Number, C =/= $_].
+
+-define(BASED_DIGIT(C, B),
+        ((?DIGIT(C) andalso C < $0 + B)
+         orelse (C >= $A andalso B > 10 andalso C < $A + B - 10)
+         orelse (C >= $a andalso B > 10 andalso C < $a + B - 10))).
+
+scan_based_int([C|Cs], St, Line, Col, Toks, {B,Ncs,Bcs}) when
+      ?BASED_DIGIT(C, B) ->
     scan_based_int(Cs, St, Line, Col, Toks, {B,[C|Ncs],Bcs});
-scan_based_int([$_|Cs], St, Line, Col, Toks, {B,Ncs,Bcs}) ->
-    scan_based_int(Cs, St, Line, Col, Toks, {B,Ncs,Bcs});
+scan_based_int([$_,Next|Cs], St, Line, Col, Toks, {B,[Prev|_]=Ncs,Bcs}) when
+      ?BASED_DIGIT(Next, B) andalso ?BASED_DIGIT(Prev, B) ->
+    scan_based_int(Cs, St, Line, Col, Toks, {B,[Next,$_|Ncs],Bcs});
 scan_based_int([]=Cs, _St, Line, Col, Toks, State) ->
     {more,{Cs,Col,Toks,Line,State,fun scan_based_int/6}};
 scan_based_int(Cs, St, Line, Col, Toks, {B,Ncs0,Bcs}) ->
     Ncs = lists:reverse(Ncs0),
-    case catch erlang:list_to_integer(Ncs, B) of
+    case catch erlang:list_to_integer(remove_digit_separators(Ncs), B) of
         N when is_integer(N) ->
             tok3(Cs, St, Line, Col, Toks, integer, Bcs++Ncs, N);
         _ ->
@@ -994,8 +998,9 @@ scan_based_int(Cs, St, Line, Col, Toks, {B,Ncs0,Bcs}) ->
 
 scan_fraction([C|Cs], St, Line, Col, Toks, Ncs) when ?DIGIT(C) ->
     scan_fraction(Cs, St, Line, Col, Toks, [C|Ncs]);
-scan_fraction([$_|Cs], St, Line, Col, Toks, Ncs) ->
-    scan_fraction(Cs, St, Line, Col, Toks, Ncs);
+scan_fraction([$_,Next|Cs], St, Line, Col, Toks, [Prev|_]=Ncs) when
+      ?DIGIT(Next) andalso ?DIGIT(Prev) ->
+    scan_fraction(Cs, St, Line, Col, Toks, [Next,$_|Ncs]);
 scan_fraction([E|Cs], St, Line, Col, Toks, Ncs) when E =:= $e; E =:= $E ->
     scan_exponent_sign(Cs, St, Line, Col, Toks, [E|Ncs]);
 scan_fraction([]=Cs, _St, Line, Col, Toks, Ncs) ->
@@ -1012,8 +1017,9 @@ scan_exponent_sign(Cs, St, Line, Col, Toks, Ncs) ->
 
 scan_exponent([C|Cs], St, Line, Col, Toks, Ncs) when ?DIGIT(C) ->
     scan_exponent(Cs, St, Line, Col, Toks, [C|Ncs]);
-scan_exponent([$_|Cs], St, Line, Col, Toks, Ncs) ->
-    scan_exponent(Cs, St, Line, Col, Toks, Ncs);
+scan_exponent([$_,Next|Cs], St, Line, Col, Toks, [Prev|_]=Ncs) when
+      ?DIGIT(Next) andalso ?DIGIT(Prev) ->
+    scan_exponent(Cs, St, Line, Col, Toks, [Next,$_|Ncs]);
 scan_exponent([]=Cs, _St, Line, Col, Toks, Ncs) ->
     {more,{Cs,Col,Toks,Line,Ncs,fun scan_exponent/6}};
 scan_exponent(Cs, St, Line, Col, Toks, Ncs) ->
@@ -1021,7 +1027,7 @@ scan_exponent(Cs, St, Line, Col, Toks, Ncs) ->
 
 float_end(Cs, St, Line, Col, Toks, Ncs0) ->
     Ncs = lists:reverse(Ncs0),
-    case catch list_to_float(Ncs) of
+    case catch list_to_float(remove_digit_separators(Ncs)) of
         F when is_float(F) ->
             tok3(Cs, St, Line, Col, Toks, float, Ncs, F);
         _ ->
-- 
2.16.4