(gud-common-init): If file arg has no directory,

let the debugger search PATH, and don't set default-directory.

1 files changed, 19 insertions, 2 deletions

diff --git a/lisp/gud.el b/lisp/gud.el
index 75e89821922..34e740bd50f 100644
--- a/lisp/gud.el
+++ b/lisp/gud.el
@@ -983,12 +983,29 @@ comint mode, which see."
                       (while (and w (= ?- (aref (car w) 0)))
                         (setq w (cdr w)))
                       (car w)))
+         (file-subst
+          (and file-word (substitute-in-file-name file-word)))
          (args (delq file-word (cdr words)))
+         ;; If a directory was specified, expand the file name.
+         ;; Otherwise, don't expand it, so GDB can use the PATH.
+         ;; A file name without directory is literally valid
+         ;; only if the file exists in ., and in that case,
+         ;; omitting the expansion here has no visible effect.
          (file (and file-word
-                    (expand-file-name (substitute-in-file-name file-word))))
+                    (if (file-name-directory file-subst)
+                        (expand-file-name file-subst)
+                      file-subst)))
          (filepart (and file-word (file-name-nondirectory file))))
     (switch-to-buffer (concat "*gud-" filepart "*"))
-    (and file-word (setq default-directory (file-name-directory file)))
+    ;; Set default-directory to the file's directory.
+    (and file-word
+         ;; Don't set default-directory if no directory was specified.
+         ;; In that case, either the file is found in the current directory,
+         ;; in which case this setq is a no-op,
+         ;; or it is found by searching PATH,
+         ;; in which case we don't know what directory it was found in.
+         (file-name-directory file)
+         (setq default-directory (file-name-directory file)))
     (or (bolp) (newline))
     (insert "Current directory is " default-directory "\n")
     (apply 'make-comint (concat "gud-" filepart) program nil