shr: fix too long lines in rendered buffers (Bug#21012)

Co-authored-by: Michael Heerdegen <michael_heerdegen@web.de>
* lisp/net/shr.el (shr-insert-document, shr-fill-text):
Correct calculation of available width.
(shr-find-fill-point): Don't overflow window edge if shr-kinsoku-shorten
is nil.

1 files changed, 42 insertions, 8 deletions

diff --git a/lisp/net/shr.el b/lisp/net/shr.el
index 60203f581ec..9116e506756 100644
--- a/lisp/net/shr.el
+++ b/lisp/net/shr.el
@@ -222,10 +222,29 @@ DOM should be a parse tree as generated by
                                      (if (not shr-use-fonts)
                                          shr-width
                                        (* shr-width (frame-char-width))))
+                                ;; We need to adjust the available
+                                ;; width for when the user disables
+                                ;; the fringes, which will cause the
+                                ;; display engine usurp one column for
+                                ;; the continuation glyph.
                                 (if (not shr-use-fonts)
-                                    (- (window-width) 2)
-                                  (- (window-pixel-width)
-                                     (* (frame-fringe-width) 2))))))
+                                    (- (window-body-width) 1
+                                       (if (and (null shr-width)
+                                                (or (zerop
+                                                     (fringe-columns 'right))
+                                                    (zerop
+                                                     (fringe-columns 'left))))
+                                           0
+                                         1))
+                                  (- (window-body-width nil t)
+                                     (* 2 (frame-char-width))
+                                     (if (and (null shr-width)
+                                              (or (zerop
+                                                   (fringe-columns 'right))
+                                                  (zerop
+                                                   (fringe-columns 'left))))
+                                         (* (frame-char-width) 2)
+                                       0))))))
     (shr-descend dom)
     (shr-fill-lines start (point))
     (shr-remove-trailing-whitespace start (point))
@@ -439,8 +458,18 @@ size, and full-buffer size."
     (with-temp-buffer
       (let ((shr-indentation 0)
             (shr-start nil)
-            (shr-internal-width (- (window-pixel-width)
-                                   (* (frame-fringe-width) 2))))
+            (shr-internal-width (- (window-body-width nil t)
+                                   (* 2 (frame-char-width))
+                                   ;; Adjust the window width for when
+                                   ;; the user disables the fringes,
+                                   ;; which causes the display engine
+                                   ;; usurp one coplumn for the
+                                   ;; continuation glyph.
+                                   (if (and (null shr-width)
+                                            (or (zerop (fringe-columns 'right))
+                                                (zerop (fringe-columns 'left))))
+                                       (* (frame-char-width) 2)
+                                     0))))
         (shr-insert text)
         (buffer-string)))))
 
@@ -620,7 +649,9 @@ size, and full-buffer size."
         ;; There's no breakable point, so we give it up.
         (let (found)
           (goto-char bp)
-          (unless shr-kinsoku-shorten
+          ;; Don't overflow the window edge, even if
+          ;; shr-kinsoku-shorten is nil.
+          (unless (or shr-kinsoku-shorten (null shr-width))
             (while (setq found (re-search-forward
                                 "\\(\\c>\\)\\| \\|\\c<\\|\\c|"
                                 (line-end-position) 'move)))
@@ -632,9 +663,12 @@ size, and full-buffer size."
        ;; Don't put kinsoku-bol characters at the beginning of a line,
        ;; or kinsoku-eol characters at the end of a line.
        (cond
-        (shr-kinsoku-shorten
+        ;; Don't overflow the window edge, even if shr-kinsoku-shorten
+        ;; is nil.
+        ((or shr-kinsoku-shorten (null shr-width))
          (while (and (not (memq (preceding-char) (list ?\C-@ ?\n ? )))
-                     (shr-char-kinsoku-eol-p (preceding-char)))
+                     (or (shr-char-kinsoku-eol-p (preceding-char))
+                         (shr-char-kinsoku-bol-p (following-char))))
            (backward-char 1))
          (when (setq failed (<= (point) start))
            ;; There's no breakable point that doesn't violate kinsoku,