From ea232a222752dd98eec8d286fee67ee8edb302f8 Mon Sep 17 00:00:00 2001
From: whispers <whispersofthedawn@duck.com>
Date: Tue, 14 Jul 2026 16:45:42 -0400
Subject: [PATCH] gawk: apply upstream patch for bug when building without
 gmp/mpfr

when using gawk 5.4.1 without gmp and mpfr, some alignment is broken in
a NODE struct. this causes build failures in downstream packages such
as `libpng` and `gcc16`. a discussion of the latter occurred on
bug-gawk (https://lists.gnu.org/archive/html/bug-gawk/2026-07/msg00013.html)
where the issue was found and pushed to the relevant branch, but has not
been released. accordingly, we fetch (manually, since fetchpatch
infrecs) the patch from the savannah gitweb. this fixes `libpng` and
`gcc16`.

(cherry picked from commit 63d29caff2227b36d40af22912af315f2aabd01b)
---
 pkgs/tools/text/gawk/default.nix              | 11 +++
 .../gawk/node-struct-without-gmp-mpfr.patch   | 79 +++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 pkgs/tools/text/gawk/node-struct-without-gmp-mpfr.patch

diff --git a/pkgs/tools/text/gawk/default.nix b/pkgs/tools/text/gawk/default.nix
index bb345afdd482..87d2946e6160 100644
--- a/pkgs/tools/text/gawk/default.nix
+++ b/pkgs/tools/text/gawk/default.nix
@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchurl,
+  fetchpatch,
   removeReferencesTo,
   runtimeShellPackage,
   texinfo,
@@ -32,6 +33,16 @@ stdenv.mkDerivation rec {
     hash = "sha256-B/b3NCt/6+QxP8LCVCrZPWT+IK2HFyABCfEFqCb1/Tc=";
   };
 
+  patches = [
+    # When building gawk without gmp and mpfr, gawk 5.4.1 causes build failures
+    # in downstream packages such as GCC and libpng.
+    # Discussion on bug-gawk:
+    # https://lists.gnu.org/archive/html/bug-gawk/2026-07/msg00013.html
+    # Vendored since we can't use fetchpatch:
+    # https://gitweb.git.savannah.gnu.org/gitweb/?p=gawk.git;a=commit;h=bf85f8a3175af703597082d4c7e0abc2066a44d3
+    ./node-struct-without-gmp-mpfr.patch
+  ];
+
   # When we do build separate interactive version, it makes sense to always include man.
   outputs = [
     "out"
diff --git a/pkgs/tools/text/gawk/node-struct-without-gmp-mpfr.patch b/pkgs/tools/text/gawk/node-struct-without-gmp-mpfr.patch
new file mode 100644
index 000000000000..01f660c191e8
--- /dev/null
+++ b/pkgs/tools/text/gawk/node-struct-without-gmp-mpfr.patch
@@ -0,0 +1,79 @@
+From bf85f8a3175af703597082d4c7e0abc2066a44d3 Mon Sep 17 00:00:00 2001
+From: "Arnold D. Robbins" <arnold@skeeve.com>
+Date: Tue, 14 Jul 2026 10:14:50 +0300
+Subject: [PATCH] Workaround fix for systems without MPFR and GMP.
+
+---
+ ChangeLog |  8 ++++++++
+ awk.h     | 23 ++++++++++++++---------
+ 2 files changed, 22 insertions(+), 9 deletions(-)
+
+diff --git a/ChangeLog b/ChangeLog
+index 6a955eed..42bd2c48 100644
+--- a/ChangeLog
++++ b/ChangeLog
+@@ -3,6 +3,14 @@
+ 	* builtin.c (do_dump_node): Add the size of each object to
+ 	the printout.
+ 
++	Unrelated: Make things works when built on systems without
++	the GMP and MPFR libraries.  Thanks to Thomas Trepl <ttrepl@yahoo.de>
++	and Bruce Dubbs <bdubbs@linuxfromscratch.org> for the reports.
++
++	* awk.h (struct exp_node): Add alignment padding when we don't
++	have MPFR. This is a hack, pending a total refactoring of
++	the NODE structure.
++
+ 2026-07-08         Arnold D. Robbins     <arnold@skeeve.com>
+ 
+ 	* 5.4.1: Release tar ball made.
+diff --git a/awk.h b/awk.h
+index dbad0d81..f4a84300 100644
+--- a/awk.h
++++ b/awk.h
+@@ -406,17 +406,24 @@ typedef struct exp_node {
+ 		} nodep;
+ 
+ 		struct {
+-#ifdef HAVE_MPFR
+ 			union {
+ 				AWKNUM fltnum;
++#ifdef HAVE_MPFR
+ 				mpfr_t mpnum;
+ 				mpz_t mpi;
+-			} nm;
+-			int rndmode;
+ #else
+-			AWKNUM fltnum;
+-			int for_alignment_only;	// especially on 32-bit
+-#endif
++				// 7/2026:
++				// This is a workaround for systems that build
++				// gawk without MPFR and GMP.  The NODE struct
++				// desperately needs to be refactored.
++#if SIZEOF_VOID_P == 4
++				char alignment[28];
++#else	// SIZEOF_VOID_P != 4
++				char alignment[48];
++#endif	// SIZEOF_VOID_P != 4
++#endif	// HAVE_MPFR
++			} nm;
++			int rndmode;	// only used for MPFR.
+ 			char *sp;
+ 			size_t slen;
+ 			int idx;
+@@ -561,10 +568,8 @@ typedef struct exp_node {
+ #ifdef HAVE_MPFR
+ #define mpg_numbr	sub.val.nm.mpnum
+ #define mpg_i		sub.val.nm.mpi
+-#define numbr		sub.val.nm.fltnum
+-#else
+-#define numbr		sub.val.fltnum
+ #endif
++#define numbr		sub.val.nm.fltnum
+ #define typed_re	sub.val.typre
+ 
+ /*
+-- 
+2.54.0
+