Handle EOF more gracefully in DAP

diff --git a/gdb/python/lib/gdb/dap/io.py b/gdb/python/lib/gdb/dap/io.py
index 2f3a2351925..367af481086 100644
--- a/gdb/python/lib/gdb/dap/io.py
+++ b/gdb/python/lib/gdb/dap/io.py
@@ -15,30 +15,44 @@ 
 
 import json
 
-from .startup import start_thread, send_gdb, log
+from .startup import start_thread, send_gdb, log, log_stack, LogLevel
 
 
 def read_json(stream):
     """Read a JSON-RPC message from STREAM.
-    The decoded object is returned."""
-    # First read and parse the header.
-    content_length = None
-    while True:
-        line = stream.readline()
-        line = line.strip()
-        if line == b"":
-            break
-        if line.startswith(b"Content-Length:"):
-            line = line[15:].strip()
-            content_length = int(line)
-            continue
-        log("IGNORED: <<<%s>>>" % line)
-    data = bytes()
-    while len(data) < content_length:
-        new_data = stream.read(content_length - len(data))
-        data += new_data
-    result = json.loads(data)
-    return result
+    The decoded object is returned.
+    None is returned on EOF."""
+    try:
+        # First read and parse the header.
+        content_length = None
+        while True:
+            line = stream.readline()
+            # If the line is empty, we hit EOF.
+            if len(line) == 0:
+                log("EOF")
+                return None
+            line = line.strip()
+            if line == b"":
+                break
+            if line.startswith(b"Content-Length:"):
+                line = line[15:].strip()
+                content_length = int(line)
+                continue
+            log("IGNORED: <<<%s>>>" % line)
+        data = bytes()
+        while len(data) < content_length:
+            new_data = stream.read(content_length - len(data))
+            # Maybe we hit EOF.
+            if len(new_data) == 0:
+                log("EOF after reading the header")
+                return None
+            data += new_data
+        return json.loads(data)
+    except OSError:
+        # Reading can also possibly throw an exception.  Treat this as
+        # EOF.
+        log_stack(LogLevel.FULL)
+        return None
 
 
 def start_json_writer(stream, queue):
diff --git a/gdb/python/lib/gdb/dap/server.py b/gdb/python/lib/gdb/dap/server.py
index 59fad59d8e6..17a41564a92 100644
--- a/gdb/python/lib/gdb/dap/server.py
+++ b/gdb/python/lib/gdb/dap/server.py
@@ -187,6 +187,8 @@  class Server:
     def _reader_thread(self):
         while True:
             cmd = read_json(self.in_stream)
+            if cmd is None:
+                break
             log("READ: <<<" + json.dumps(cmd) + ">>>")
             # Be extra paranoid about the form here.  If anything is
             # missing, it will be put in the queue and then an error
@@ -201,6 +203,8 @@  class Server:
             ):
                 self.canceller.cancel(cmd["arguments"]["requestId"])
             self.read_queue.put(cmd)
+        # When we hit EOF, signal it with None.
+        self.read_queue.put(None)
 
     @in_dap_thread
     def main_loop(self):
@@ -212,6 +216,9 @@  class Server:
         start_thread("JSON reader", self._reader_thread)
         while not self.done:
             cmd = self.read_queue.get()
+            # A None value here means the reader hit EOF.
+            if cmd is None:
+                break
             result = self._handle_command(cmd)
             self._send_json(result)
             events = self.delayed_events
diff --git a/gdb/testsuite/gdb.dap/eof.exp b/gdb/testsuite/gdb.dap/eof.exp
new file mode 100644
index 00000000000..139c17ad335
--- /dev/null
+++ b/gdb/testsuite/gdb.dap/eof.exp
@@ -0,0 +1,37 @@ 
+# Copyright 2024 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test that EOF is handled gracefully.
+
+require allow_dap_tests
+
+load_lib dap-support.exp
+
+# The test doesn't matter much.
+standard_testfile scopes.c
+
+if {[build_executable ${testfile}.exp $testfile $srcfile] == -1} {
+    return
+}
+
+if {[dap_launch $testfile] == ""} {
+    return
+}
+
+catch "close -i $gdb_spawn_id"
+catch "wait -i $gdb_spawn_id"
+unset gdb_spawn_id
+
+dap_check_log_file
diff --git a/gdb/testsuite/lib/dap-support.exp b/gdb/testsuite/lib/dap-support.exp
index bafcd9b6fc7..72b6ac537c3 100644
--- a/gdb/testsuite/lib/dap-support.exp
+++ b/gdb/testsuite/lib/dap-support.exp
@@ -339,7 +339,7 @@  proc dap_target_remote {target} {
 }
 
 # Read the most recent DAP log file and check it for exceptions.
-proc _dap_check_log_file {} {
+proc dap_check_log_file {} {
     global dap_gdb_instance
 
     set fd [open [standard_output_file "dap.log.$dap_gdb_instance"]]
@@ -366,7 +366,7 @@  proc _dap_check_log_file {} {
 proc dap_shutdown {{terminate false}} {
     dap_check_request_and_response "shutdown" disconnect \
 	[format {o terminateDebuggee [l %s]} $terminate]
-    _dap_check_log_file
+    dap_check_log_file
 }
 
 # Search the event list EVENTS for an output event matching the regexp