Change end of trimmed long window titles to . . .

Improves: QubesOS/qubes-issues#5986

Author: alimirjamali

.gitignore

@@ -12,4 +12,5 @@ xf86-qubes-common/libxf86-qubes-common.so
 /pipewire/pw-module-run
 *.dep
 /gui-agent/qubes-gui
+/gui-agent/qubes-gui-runuser
 /gui-common/qubes-gui-runuser

archlinux/PKGBUILD.in

@@ -23,6 +23,7 @@ makedepends=(
     libxcomposite
     libxt
     libxdamage
+    libunistring
     pixman
     lsb-release
     'qubes-vm-gui-common>=4.3.0'
@@ -57,6 +58,7 @@ package_qubes-vm-gui() {
     'zenity'
     'qubes-libvchan'
     'python-xcffib'
+    'libunistring'
     # Xorg dependencies are on specific ABI versions: https://www.x.org/wiki/XorgModuleABIVersions/
     # These can also be verified with pacman -Qi xorg-server (Provides)
     # There is however a discrepancy if verifying via pkg-config --variable abi_videodrv xorg-server

debian/control

@@ -25,6 +25,7 @@ Build-Depends:
     qubes-gui-common (>= 4.3.0),
     qubesdb-dev,
     libltdl-dev,
+    libunistring-dev,
 Standards-Version: 4.4.0.1
 Homepage: http://www.qubes-os.org/
 #Vcs-Git: git://git.debian.org/collab-maint/qubes-gui-agent.git

gui-agent/Makefile

@@ -24,7 +24,8 @@ CFLAGS += -I../include/ `pkg-config --cflags vchan` -g -Wall -Wextra -Werror -fP
 	  -Wmissing-prototypes -Wstrict-prototypes -Wold-style-declaration \
 	  -Wold-style-definition
 OBJS = vmside.o txrx-vchan.o error.o list.o encoding.o
-LIBS = -lX11 -lXdamage -lXcomposite -lXfixes `pkg-config --libs vchan` -lqubesdb
+LIBS = -lX11 -lXdamage -lXcomposite -lXfixes `pkg-config --libs vchan` -lqubesdb \
+	   -lunistring
 
 
 all: qubes-gui qubes-gui-runuser

gui-agent/vmside.c

@@ -53,6 +53,7 @@
 #include "encoding.h"
 #include <libvchan.h>
 #include <poll.h>
+#include "unistr.h"
 
 
 #include <linux/input.h>
@@ -651,6 +652,27 @@ void send_wmname(Ghandles * g, XID window)
     if (!get_net_wmname(g, window, msg.data, sizeof(msg.data)))
         if (!getwmname_tochar(g, window, msg.data, sizeof(msg.data)))
             return;
+    if (strlen(msg.data) == sizeof(msg.data) - 1) {
+        // Window title might had been longer than output buffer.
+        // Trim at correct utf8 boundary and set end to . . .
+        msg.data[sizeof(msg.data) - 7] = 0;
+        for (int i=0; i < 4; i++) {
+            uint8_t * last_byte = (uint8_t *)msg.data + strlen(msg.data) - 1;
+            // check for valid 1, 2, 3 or 4 byte uft8 char at the end of string
+            if (
+                !u8_check(last_byte, 1) ||
+                !u8_check(last_byte - 1, 2) ||
+                !u8_check(last_byte - 2, 3) ||
+                !u8_check(last_byte - 3, 4)
+            ) {
+                break;
+            } else {
+                // trim one invalid byte at end of string
+                msg.data[strlen(msg.data) - 1] = 0;
+            }
+        }
+        strncat(msg.data, " . . .", sizeof(msg.data) - 1);
+    }
     hdr.window = window;
     hdr.type = MSG_WMNAME;
     write_message(g->vchan, hdr, msg);

rpm_spec/gui-agent.spec.in

@@ -75,6 +75,7 @@ BuildRequires:	qubes-gui-common-devel >= 4.3.0
 BuildRequires:	qubes-db-devel
 BuildRequires:	xen-devel
 BuildRequires:	systemd-rpm-macros
+BuildRequires:	libunistring-devel
 %if 0%{?is_opensuse}
 # for directory ownership
 BuildRequires:  xinit
@@ -102,6 +103,7 @@ Requires:   xev
 Requires:   xdpyinfo
 Requires:   xprop
 Requires:   xrandr
+Requires:   libunistring
 
 Provides:   qubes-gui-vm = %{version}-%{release}
 Obsoletes:  qubes-gui-vm < 4.0.0