master 5629af9: Allow disabling the BPA part of bidi reordering

[Eli Zaretskii]

branch: master
commit 5629af9cbe91feee8fb4d896224ed62e455f951d
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Allow disabling the BPA part of bidi reordering
    
    * src/xdisp.c (syms_of_xdisp): New variable 'bidi-inhibit-bpa'.
    * src/bidi.c (bidi_paired_bracket_type): If 'bidi-inhibit-bpa'
    is non-nil, return BIDI_BRACKET_NONE for all characters.
    
    * lisp/frame.el: Add 'bidi-inhibit-bpa' to the list of
    variables whose changes require redisplay.  (Bug#38407)
---
 lisp/frame.el | 3 ++-
 src/bidi.c    | 2 +-
 src/xdisp.c   | 8 ++++++++
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/lisp/frame.el b/lisp/frame.el
index 1a15a4c..1d1dcab 100644
--- a/lisp/frame.el
+++ b/lisp/frame.el
@@ -2736,7 +2736,8 @@ See also `toggle-frame-maximized'."
         display-fill-column-indicator-column
         display-fill-column-indicator-character
         bidi-paragraph-direction
-        bidi-display-reordering))
+        bidi-display-reordering
+        bidi-inhibit-bpa))
 
 (provide 'frame)
 
diff --git a/src/bidi.c b/src/bidi.c
index 1430d22..cb94c4e 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -404,7 +404,7 @@ bidi_mirror_char (int c)
 static bidi_bracket_type_t
 bidi_paired_bracket_type (int c)
 {
-  if (c == BIDI_EOB)
+  if (c == BIDI_EOB || bidi_inhibit_bpa)
     return BIDI_BRACKET_NONE;
   if (c < 0 || c > MAX_CHAR)
     emacs_abort ();
diff --git a/src/xdisp.c b/src/xdisp.c
index c4d23be..2467b33 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -34839,6 +34839,14 @@ Intended for use during debugging and for testing bidi 
display;
 see biditest.el in the test suite.  */);
   inhibit_bidi_mirroring = false;
 
+  DEFVAR_BOOL ("bidi-inhibit-bpa", bidi_inhibit_bpa,
+    doc: /* Non-nil means inhibit the Bidirectional Parentheses Algorithm.
+Disabling the BPA makes redisplay faster, but might produce incorrect
+display reordering of bidirectional text with embedded parentheses and
+other bracket characters whose 'paired-bracket' Unicode property is
+non-nil, see `get-char-code-property'.  */);
+  bidi_inhibit_bpa = false;
+
 #ifdef GLYPH_DEBUG
   DEFVAR_BOOL ("inhibit-try-window-id", inhibit_try_window_id,
               doc: /* Inhibit try_window_id display optimization.  */);