emacs-29 79971ebacc: Disable and document 'doc-view-mupdf-use-svg' (bug#58041)

[Eli Zaretskii]

branch: emacs-29
commit 79971ebacc7ea114cbb9210d3505a576c95b2964
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Disable and document 'doc-view-mupdf-use-svg' (bug#58041)
    
    * lisp/doc-view.el (doc-view-mupdf-use-svg): Disable by default.
    * etc/NEWS: Document.  Patch by Visuwesh <visuweshm@gmail.com>.
    Do not merge to master.
---
 etc/NEWS         | 14 ++++++++++++++
 lisp/doc-view.el |  4 ++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index 08c7f8a4dd..fa28ba465f 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1636,6 +1636,20 @@ randomness as before, or to use a bag).
 *** New user option 'battery-update-functions'.
 This can be used to trigger actions based on the battery status.
 
+** DocView
+
+*** doc-view can now generate SVG images when viewing PDF files.
+If Emacs is built with SVG support, doc-view can generate SVG files
+when using MuPDF as the converter for PDF files, which generally leads
+to sharper images (especially when zooming), and allows customization
+of background and foreground color of the page via the new user
+options 'doc-view-svg-background' and 'doc-view-svg-foreground'.  To
+activate this behaviour, set 'doc-view-mupdf-use-svg' to non-nil if
+your Emacs has SVG support.  Note that, with some versions of MuPDF,
+SVG generation is known to sometimes produce SVG files that are buggy
+or can take a long time to render.
+
+
 ** Enriched Mode
 
 +++
diff --git a/lisp/doc-view.el b/lisp/doc-view.el
index 7c272f52fb..427da557d2 100644
--- a/lisp/doc-view.el
+++ b/lisp/doc-view.el
@@ -209,8 +209,8 @@ are available (see Info node `(emacs)Document View')."
           function)
   :version "24.4")
 
-(defcustom doc-view-mupdf-use-svg (image-type-available-p 'svg)
-  "Whether to use svg images for PDF files."
+(defcustom doc-view-mupdf-use-svg nil
+  "Whether to use SVG images for PDF files."
   :type 'boolean
   :version "29.1")