bug#39408: Breakpoints don't work with M-x gdb under TRAMP

[Jim Porter <jporterbugs@gmail.com>]

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This is already fixed in Emacs 28 thanks to bug#44173 (a78c614), which
replaces the old GDB/MI parser (that converted the data to JSON first)
with a more-robust parser. Attached is a patch to fix this under Emacs
27.

The problem is that in `gdb-jsonify-buffer', when replacing the
"fullname" with a Tramp path, the wildcard was greedy, resulting in
only one "fullname" being replaced in the buffer. This had the effect
of rendering it impossible to have more than one breakpoint, as all
but the first breakpoint would have unmodified "fullname"s.

(Note: I have a couple of patches in Tramp already that put me at the
limit for patches without copyright assignment paperwork. However,
I've already requested the form.)

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From 2ab1ecef679df32230705e37098c1d93c639c22f Mon Sep 17 00:00:00 2001
From: Jim Porter <jporterbugs@gmail.com>
Date: Thu, 15 Apr 2021 21:39:03 -0700
Subject: [PATCH 1/2] Fix setting breakpoints in M-x gdb for remote files

* lisp/progmodes/gdb-mi.el (gdb-jsonify-buffer): Fix modification of
GDB/MI "fullname" property for remote files
---
 lisp/progmodes/gdb-mi.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/progmodes/gdb-mi.el b/lisp/progmodes/gdb-mi.el
index 65fe997341..1b2642fae7 100644
--- a/lisp/progmodes/gdb-mi.el
+++ b/lisp/progmodes/gdb-mi.el
@@ -2696,7 +2696,7 @@ If `default-directory' is remote, full file names are adapted accordingly."
     (let ((remote (file-remote-p default-directory)))
       (when remote
         (goto-char (point-min))
-        (while (re-search-forward "[\\[,]fullname=\"\\(.+\\)\"" nil t)
+        (while (re-search-forward "[\\[,]fullname=\"\\(.+?\\)\"" nil t)
           (replace-match (concat remote "\\1") nil nil nil 1))))
     (goto-char (point-min))
     (when fix-key
-- 
2.25.1