emacs-29 7d787564c08: Actually improve detection of long lines

[Gregory Heytings]

branch: emacs-29
commit 7d787564c08351b275e8f729e8e9f1ec2ae8fe04
Author: Gregory Heytings <gregory@heytings.org>
Commit: Gregory Heytings <gregory@heytings.org>

    Actually improve detection of long lines
    
    * src/xdisp.c (redisplay_window): Update condition.
    
    * src/xdisp.c (mark_window_display_accurate_1):
    * src/pdumper.c (dump_buffer):
    * src/buffer.h (BUF_CHARS_UNCHANGED_MODIFIED):
    (struct buffer_text):
    * src/buffer.c (Fget_buffer_create):
    Revert 1c837c42c2, which was misguided.
---
 src/buffer.c  |  1 -
 src/buffer.h  | 11 -----------
 src/pdumper.c |  1 -
 src/xdisp.c   |  3 +--
 4 files changed, 1 insertion(+), 15 deletions(-)

diff --git a/src/buffer.c b/src/buffer.c
index 71be7ed9e13..69f27c9f476 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -604,7 +604,6 @@ even if it is dead.  The return value is never nil.  */)
   set_buffer_intervals (b, NULL);
   BUF_UNCHANGED_MODIFIED (b) = 1;
   BUF_OVERLAY_UNCHANGED_MODIFIED (b) = 1;
-  BUF_CHARS_UNCHANGED_MODIFIED (b) = 1;
   BUF_END_UNCHANGED (b) = 0;
   BUF_BEG_UNCHANGED (b) = 0;
   *(BUF_GPT_ADDR (b)) = *(BUF_Z_ADDR (b)) = 0; /* Put an anchor '\0'.  */
diff --git a/src/buffer.h b/src/buffer.h
index dded0cd98c1..80b3fd81e09 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -149,18 +149,12 @@ enum { BEG = 1, BEG_BYTE = BEG };
 #define BUF_BEG_UNCHANGED(buf) ((buf)->text->beg_unchanged)
 #define BUF_END_UNCHANGED(buf) ((buf)->text->end_unchanged)
 
-#define BUF_CHARS_UNCHANGED_MODIFIED(buf) \
-  ((buf)->text->chars_unchanged_modified)
-
 #define UNCHANGED_MODIFIED \
   BUF_UNCHANGED_MODIFIED (current_buffer)
 #define OVERLAY_UNCHANGED_MODIFIED \
   BUF_OVERLAY_UNCHANGED_MODIFIED (current_buffer)
 #define BEG_UNCHANGED BUF_BEG_UNCHANGED (current_buffer)
 #define END_UNCHANGED BUF_END_UNCHANGED (current_buffer)
-
-#define CHARS_UNCHANGED_MODIFIED \
-  BUF_CHARS_UNCHANGED_MODIFIED (current_buffer)
 
 /* Functions to set PT in the current buffer, or another buffer.  */
 
@@ -274,11 +268,6 @@ struct buffer_text
        end_unchanged contain no useful information.  */
     modiff_count overlay_unchanged_modified;
 
-    /* CHARS_MODIFF as of last redisplay that finished.  It's used
-       when we only care about changes in actual buffer text, not in
-       any other kind of changes, like properties etc.  */
-    modiff_count chars_unchanged_modified;
-
     /* Properties of this buffer's text.  */
     INTERVAL intervals;
 
diff --git a/src/pdumper.c b/src/pdumper.c
index fedcd3e4044..263343f60be 100644
--- a/src/pdumper.c
+++ b/src/pdumper.c
@@ -2811,7 +2811,6 @@ dump_buffer (struct dump_context *ctx, const struct 
buffer *in_buffer)
       DUMP_FIELD_COPY (out, buffer, own_text.end_unchanged);
       DUMP_FIELD_COPY (out, buffer, own_text.unchanged_modified);
       DUMP_FIELD_COPY (out, buffer, own_text.overlay_unchanged_modified);
-      DUMP_FIELD_COPY (out, buffer, own_text.chars_unchanged_modified);
       if (buffer->own_text.intervals)
         dump_field_fixup_later (ctx, out, buffer, &buffer->own_text.intervals);
       dump_field_lv_rawptr (ctx, out, buffer, &buffer->own_text.markers,
diff --git a/src/xdisp.c b/src/xdisp.c
index 255851b9213..d14cd468191 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -17264,7 +17264,6 @@ mark_window_display_accurate_1 (struct window *w, bool 
accurate_p)
 
       BUF_UNCHANGED_MODIFIED (b) = BUF_MODIFF (b);
       BUF_OVERLAY_UNCHANGED_MODIFIED (b) = BUF_OVERLAY_MODIFF (b);
-      BUF_CHARS_UNCHANGED_MODIFIED (b) = BUF_CHARS_MODIFF (b);
       BUF_BEG_UNCHANGED (b) = BUF_GPT (b) - BUF_BEG (b);
       BUF_END_UNCHANGED (b) = BUF_Z (b) - BUF_GPT (b);
 
@@ -19535,7 +19534,7 @@ redisplay_window (Lisp_Object window, bool 
just_this_one_p)
   /* Check whether the buffer to be displayed contains long lines.  */
   if (!NILP (Vlong_line_threshold)
       && !current_buffer->long_line_optimizations_p
-      && (CHARS_MODIFF - CHARS_UNCHANGED_MODIFIED > 8
+      && (CHARS_MODIFF - UNCHANGED_MODIFIED > 8
          || current_buffer->clip_changed))
     {
       ptrdiff_t cur, next, found, max = 0, threshold;