ptex: fix segmentation fault for disp_node-only paragraphs in line_break

git-svn-id: svn://tug.org/texlive/trunk@59697 c570f23f-e606-0410-a88d-b1316a301751

4 files changed, 34 insertions, 2 deletions

diff --git a/Build/source/texk/web2c/eptexdir/ChangeLog b/Build/source/texk/web2c/eptexdir/ChangeLog
index 7c10d9ef1dd..09ad2fa3f4b 100644
--- a/Build/source/texk/web2c/eptexdir/ChangeLog
+++ b/Build/source/texk/web2c/eptexdir/ChangeLog
@@ -1,3 +1,8 @@
+2021-06-25  Hironori Kitagawa  <h_kitagawa2001@yahoo.co.jp>
+
+	* etex.ch1: Adapt to ptex-base.ch for fix of
+	https://github.com/texjporg/tex-jp-build/issues/123
+
 2021-03-23  Karl Berry  <karl@tug.org>
 
 	* TL'21.
diff --git a/Build/source/texk/web2c/eptexdir/etex.ch1 b/Build/source/texk/web2c/eptexdir/etex.ch1
index 7e9e789486f..aa1d33c3752 100644
--- a/Build/source/texk/web2c/eptexdir/etex.ch1
+++ b/Build/source/texk/web2c/eptexdir/etex.ch1
@@ -154,6 +154,16 @@ change_box(q);
 @z
 
 @x [48.1145]
+  pop_nest; w:=-max_dimen;
+  end
+  { |disp_node|-only paragraphs are ignored }
+@y
+  @<Prepare for display after an empty paragraph@>
+  end
+  { |disp_node|-only paragraphs are ignored }
+@z
+
+@x [48.1145]
 else  begin adjust_hlist(head,true); line_break(display_widow_penalty);@/
 @y
 else  begin adjust_hlist(head,true); line_break(true);@/
diff --git a/Build/source/texk/web2c/ptexdir/ChangeLog b/Build/source/texk/web2c/ptexdir/ChangeLog
index 78e691a28de..a0d629e2a54 100644
--- a/Build/source/texk/web2c/ptexdir/ChangeLog
+++ b/Build/source/texk/web2c/ptexdir/ChangeLog
@@ -1,3 +1,12 @@
+2021-06-25  Hironori Kitagawa  <h_kitagawa2001@yahoo.co.jp>
+	and Hironobu Yamashita  <h.y.acetaminophen@gmail.com>
+
+	* ptex-base.ch (end_graf, @<Go into display math mode@>):
+	Ignore disp_node-only paragraphs.
+	* ptex-base.ch (line_break): consider when link(temp_head)=tail
+	and it is a disp_node.
+	https://github.com/texjporg/tex-jp-build/issues/123
+
 2021-03-23  Karl Berry  <karl@tug.org>
 
 	* TL'21.
diff --git a/Build/source/texk/web2c/ptexdir/ptex-base.ch b/Build/source/texk/web2c/ptexdir/ptex-base.ch
index c1b23f1c8c7..bb45acdb3c1 100644
--- a/Build/source/texk/web2c/ptexdir/ptex-base.ch
+++ b/Build/source/texk/web2c/ptexdir/ptex-base.ch
@@ -4185,10 +4185,10 @@ first_use:=true; chain:=false;
 delete_glue_ref(cur_kanji_skip); delete_glue_ref(cur_xkanji_skip);
 cur_kanji_skip:=space_ptr(head); cur_xkanji_skip:=xspace_ptr(head);
 add_glue_ref(cur_kanji_skip); add_glue_ref(cur_xkanji_skip);
-link(temp_head):=link(head);
 if not is_char_node(tail)and(type(tail)=disp_node) then
   begin free_node(tail,small_node_size); tail:=prev_node; link(tail):=null
   end;
+link(temp_head):=link(head);
 if is_char_node(tail) then tail_append(new_penalty(inf_penalty))
 else if type(tail)<>glue_node then tail_append(new_penalty(inf_penalty))
 @z
@@ -5274,7 +5274,10 @@ mode:=hmode; space_factor:=1000; set_cur_lang; clang:=cur_lang;
   begin if head=tail then pop_nest {null paragraphs are ignored}
   else line_break(widow_penalty);
 @y
-  begin if head=tail then pop_nest {null paragraphs are ignored}
+  begin if (link(head)=tail)and(not is_char_node(tail)and(type(tail)=disp_node)) then
+    begin free_node(tail,small_node_size); tail:=head; link(head):=null; end;
+    { |disp_node|-only paragraphs are ignored }
+  if head=tail then pop_nest {null paragraphs are ignored}
   else begin adjust_hlist(head,true); line_break(widow_penalty)
        end;
 @z
@@ -5732,6 +5735,11 @@ direction:=-abs(direction);
 @x [48.1145] l.22435 - pTeX: Call adjust_hlist at begin of display
 else  begin line_break(display_widow_penalty);@/
 @y
+else if (link(head)=tail)and(not is_char_node(tail)and(type(tail)=disp_node)) then
+  begin free_node(tail,small_node_size); tail:=head; link(head):=null;
+  pop_nest; w:=-max_dimen;
+  end
+  { |disp_node|-only paragraphs are ignored }
 else  begin adjust_hlist(head,true); line_break(display_widow_penalty);@/
 @z