Mention crashes due to Noto Serif Kannada fonts

* etc/PROBLEMS: Mention crashes due to Noto Serif Kannada fonts,
and the respective workarounds.  (Bug#30193)

1 files changed, 27 insertions, 6 deletions

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index 32f12eab62e..c194ba53145 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -241,12 +241,33 @@ before starting Emacs, or run Emacs as root.
 
 ** Emacs crashes when you try to view a file with complex characters.
 
-For example, the etc/HELLO file (as shown by C-h h).
-The message "symbol lookup error: /usr/bin/emacs: undefined symbol: OTF_open"
-is shown in the terminal from which you launched Emacs.
-This problem only happens when you use a graphical display (ie not
-with -nw) and compiled Emacs with the "libotf" library for complex
-text handling.
+One possible reason for this could be a bug in the libotf or the
+libm17n-flt/m17n-db libraries Emacs uses for displaying complex
+scripts.  Make sure you have the latest versions of these libraries
+installed.  If the problem still persists with the latest released
+versions of these libraries, you can try building these libraries from
+their CVS repository:
+
+  cvs -z3 -d:pserver:anonymous@cvs.savannah.nongnu.org:/sources/m17n co libotf
+  cvs -z3 -d:pserver:anonymous@cvs.savannah.nongnu.org:/sources/m17n co m17n-db
+  cvs -z3 -d:pserver:anonymous@cvs.savannah.nongnu.org:/sources/m17n co m17n-lib
+
+One known problem that causes such crashes is with using Noto Serif
+Kannada fonts.  To work around that, force Emacs not to select these
+fonts, by adding the following to your ~/.emacs init file:
+
+  (push "Noto Serif Kannada" face-ignored-fonts)
+
+You can try this interactively in a running Emacs session like this:
+
+  M-: (push "Noto Serif Kannada" face-ignored-fonts) RET
+
+Another set of problems is caused by an incompatible libotf library.
+In this case, displaying the etc/HELLO file (as shown by C-h h)
+triggers the following message to be shown in the terminal from which
+you launched Emacs:
+
+  symbol lookup error: /usr/bin/emacs: undefined symbol: OTF_open
 
 This problem occurs because unfortunately there are two libraries
 called "libotf".  One is the library for handling OpenType fonts,