12/15: gnu: slim: Fix build failure with GCC-11

[guix-commits]

civodul pushed a commit to branch master
in repository guix.

commit efce51a194a7a05860a4d489ccb3f3b7c4d5985a
Author: Brian Cully <bjc@spork.org>
AuthorDate: Fri Apr 28 17:25:22 2023 -0400

    gnu: slim: Fix build failure with GCC-11
    
    GCC-11 sniffed out a long-standing bug where a pointer was being tested for 
a
    negative value, which is impossible. Instead, check for NULL, which is how 
the
    error result is actually returned.
    
    See https://github.com/iwamatsu/slim/issues/14 for details.
    
    Fixes <https://issues.guix.gnu.org/63155>.
    
    * gnu/packages/display-managers.scm (slim) [fix-0-pointer-comparison]: new
    phase
    
    Signed-off-by: Ludovic Courtès <ludo@gnu.org>
---
 gnu/packages/display-managers.scm | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/display-managers.scm 
b/gnu/packages/display-managers.scm
index b0d388f1bc..c1a08e8553 100644
--- a/gnu/packages/display-managers.scm
+++ b/gnu/packages/display-managers.scm
@@ -475,7 +475,11 @@ GTK+, lets you select a desktop session and log in to it.")
                ;; The build system's logic here is: if "Linux", then
                 ;; "systemd".  Strip that.
                 ""))
-             #t)))
+             #t))
+         (add-before 'configure 'fix-0-pointer-comparison
+           (lambda _
+             (substitute* "panel.cpp"
+               (("WinGC < 0") "WinGC == NULL")))))
        #:configure-flags '("-DUSE_PAM=yes"
                            "-DUSE_CONSOLEKIT=no")
        #:tests? #f))