From bf5cf73b0a7f64bca732f876d35186f39ae4de21 Mon Sep 17 00:00:00 2001
From: "J. T. Elscott" <78996170+99jte@users.noreply.github.com>
Date: Thu, 13 Mar 2025 10:05:47 -0700
Subject: [PATCH 1/3] kdePackages.khelpcenter: fix manpage search

Previously the shebang in khc_mansearch.py pointed to /bin/env and caused it to fail; add python3 to the extraBuildInputs to that it gets converted to a nix path.
Also get the man-db binaries by their nix path rather than hoping that they're in the runtime PATH.
---
 pkgs/kde/gear/khelpcenter/default.nix         |  9 ++++++++
 ...se_nix_paths_for_mansearch_utilities.patch | 23 +++++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100644 pkgs/kde/gear/khelpcenter/use_nix_paths_for_mansearch_utilities.patch

diff --git a/pkgs/kde/gear/khelpcenter/default.nix b/pkgs/kde/gear/khelpcenter/default.nix
index 2348754b71b6..e69cd63a7d53 100644
--- a/pkgs/kde/gear/khelpcenter/default.nix
+++ b/pkgs/kde/gear/khelpcenter/default.nix
@@ -1,7 +1,10 @@
 {
   mkKdeDerivation,
+  replaceVars,
   qtwebengine,
   xapian,
+  man-db,
+  python3,
 }:
 mkKdeDerivation {
   pname = "khelpcenter";
@@ -9,6 +12,12 @@ mkKdeDerivation {
   extraBuildInputs = [
     qtwebengine
     xapian
+    python3
+  ];
+  patches = [
+    (replaceVars ./use_nix_paths_for_mansearch_utilities.patch {
+      inherit man-db;
+    })
   ];
   meta.mainProgram = "khelpcenter";
 }
diff --git a/pkgs/kde/gear/khelpcenter/use_nix_paths_for_mansearch_utilities.patch b/pkgs/kde/gear/khelpcenter/use_nix_paths_for_mansearch_utilities.patch
new file mode 100644
index 000000000000..531819730127
--- /dev/null
+++ b/pkgs/kde/gear/khelpcenter/use_nix_paths_for_mansearch_utilities.patch
@@ -0,0 +1,23 @@
+diff --git a/searchhandlers/khc_mansearch.py b/searchhandlers/khc_mansearch.py
+index ce61ed9c..a8c4c653 100755
+--- a/searchhandlers/khc_mansearch.py
++++ b/searchhandlers/khc_mansearch.py
+@@ -32,15 +32,15 @@ def main():
+     # If the query is a single word, perhaps it is the literal name of the
+     # command, or a prefix, or a substring
+     if not ' ' in words:
+-        results_prefix = subprocess.run(['whatis', '-w', words + '*'], capture_output=True, text=True)
++        results_prefix = subprocess.run(['@man-db@/bin/whatis', '-w', words + '*'], capture_output=True, text=True)
+         if results_prefix.returncode == 0:
+             command_results += results_prefix.stdout
+-        results_substring = subprocess.run(['whatis', '-w', '*' + words + '*'], capture_output=True, text=True)
++        results_substring = subprocess.run(['@man-db@/bin/whatis', '-w', '*' + words + '*'], capture_output=True, text=True)
+         if results_substring.returncode == 0:
+             command_results += results_substring.stdout
+ 
+     # Build the apropos command line
+-    apropos = ['apropos', '-L', args.lang]
++    apropos = ['@man-db@/bin/apropos', '-L', args.lang]
+     if args.method == 'and':
+         apropos.append('--and')
+     apropos.extend(words.split(' '))

From 513de13f422f23f358e4d38149c8ce83fe2e3aa3 Mon Sep 17 00:00:00 2001
From: "J. T. Elscott" <78996170+99jte@users.noreply.github.com>
Date: Thu, 13 Mar 2025 10:08:44 -0700
Subject: [PATCH 2/3] kdePackages.khelpcenter: runtime dependency on kio-extras
 (through wrapQtAppsHook) to retrieve manpages

---
 pkgs/kde/gear/khelpcenter/default.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkgs/kde/gear/khelpcenter/default.nix b/pkgs/kde/gear/khelpcenter/default.nix
index e69cd63a7d53..795ec3b4aeb3 100644
--- a/pkgs/kde/gear/khelpcenter/default.nix
+++ b/pkgs/kde/gear/khelpcenter/default.nix
@@ -5,6 +5,7 @@
   xapian,
   man-db,
   python3,
+  kio-extras,
 }:
 mkKdeDerivation {
   pname = "khelpcenter";
@@ -13,6 +14,7 @@ mkKdeDerivation {
     qtwebengine
     xapian
     python3
+    kio-extras
   ];
   patches = [
     (replaceVars ./use_nix_paths_for_mansearch_utilities.patch {

From 615baa8d74c4dc707e8027eeafe57ffadddd9ebf Mon Sep 17 00:00:00 2001
From: "J. T. Elscott" <78996170+99jte@users.noreply.github.com>
Date: Thu, 13 Mar 2025 10:18:11 -0700
Subject: [PATCH 3/3] kdePackages.kio-extras: add a manpage search path for
 nixos

Add the path /run/current-system/etc/man_db.conf. With my previous commits in this PR, khelpcenter is able to search for manpages because it calls out to man-db, but it doesn't know where to find them when asked to display them.
---
 .../kio-extras/add-nixos-man-db-config-path.patch   | 13 +++++++++++++
 pkgs/kde/gear/kio-extras/default.nix                |  4 ++++
 2 files changed, 17 insertions(+)
 create mode 100644 pkgs/kde/gear/kio-extras/add-nixos-man-db-config-path.patch

diff --git a/pkgs/kde/gear/kio-extras/add-nixos-man-db-config-path.patch b/pkgs/kde/gear/kio-extras/add-nixos-man-db-config-path.patch
new file mode 100644
index 000000000000..275e6121c17f
--- /dev/null
+++ b/pkgs/kde/gear/kio-extras/add-nixos-man-db-config-path.patch
@@ -0,0 +1,13 @@
+diff --git a/man/kio_man.cpp b/man/kio_man.cpp
+index a2fb6dbf5..cb6f373bc 100644
+--- a/man/kio_man.cpp
++++ b/man/kio_man.cpp
+@@ -868,6 +868,8 @@ void MANProtocol::constructPath(QStringList &constr_path, QStringList constr_cat
+         mc.setFileName("/etc/manpath.config"); // SuSE, Debian
+     if (!mc.exists())
+         mc.setFileName("/etc/man.config"); // Mandrake
++    if (!mc.exists())
++        mc.setFileName("/run/current-system/etc/man_db.conf"); // NixOS
+ 
+     if (mc.open(QIODevice::ReadOnly)) {
+         QTextStream is(&mc);
diff --git a/pkgs/kde/gear/kio-extras/default.nix b/pkgs/kde/gear/kio-extras/default.nix
index 2260feeac62c..5bcf4b605069 100644
--- a/pkgs/kde/gear/kio-extras/default.nix
+++ b/pkgs/kde/gear/kio-extras/default.nix
@@ -19,6 +19,10 @@
 mkKdeDerivation {
   pname = "kio-extras";
 
+  patches = [
+    # An upstream merge request is pending for this https://invent.kde.org/network/kio-extras/-/merge_requests/422
+    ./add-nixos-man-db-config-path.patch
+  ];
   extraNativeBuildInputs = [
     pkg-config
     gperf