libcmd: remove support for lowdown < 1.4.0

NixOS 25.05 which distributed lowdown < 1.4 has been EOL for a bit now,
25.11 ships lowdown 2.0.4.

Dropping support means we can tweak the lowdown options for terminal
output which have been added in 1.4.0 without having diverging behavior
in possible builds of Lix.

Change-Id: Icae97cf5e9e680766b8a6f4e85514f4c4625d1dd

doc/manual/change-authors.yml

@@ -252,6 +252,10 @@ rootile:
 seppel3210:
   github: Seppel3210
 
+sterni:
+  forgejo: sterni
+  github: sternenseemann
+
 stevalkr:
   github: stevalkr
 

doc/manual/rl-next/minimum-lowdown-1.4.md

@@ -0,0 +1,10 @@
+---
+synopsis: "Lix now requires lowdown 1.4.0 or later"
+issues: []
+cls: [5374]
+category: Packaging
+credits: [sterni]
+---
+
+Support for linking against `lowdown < 1.4.0` has been removed from Lix since
+all supported Nixpkgs channels distribute lowdown 2.0.4 or later.

lix/libcmd/markdown.cc

@@ -55,7 +55,6 @@ std::string renderMarkdownToTerminal(std::string_view markdown, StandardOutputSt
 
     struct lowdown_opts opts{
         .type = LOWDOWN_TERM,
-#ifdef LOWDOWN_SEPARATE_TERM_OPTS
         .term =
             {
                 .cols = lowdown_cols,
@@ -65,14 +64,7 @@ std::string renderMarkdownToTerminal(std::string_view markdown, StandardOutputSt
                 .vmargin = 0,
                 .centre = 0,
             },
-        // maxdepth needs to be part of the ifdefs to match declaration order
         .maxdepth = 20,
-#else
-        .maxdepth = 20,
-        .cols = lowdown_cols,
-        .hmargin = 0,
-        .vmargin = 0,
-#endif /* LOWDOWN_SEPARATE_TERM_OPTS */
         .feat = LOWDOWN_COMMONMARK | LOWDOWN_FENCED | LOWDOWN_DEFLIST | LOWDOWN_TABLES,
 #ifdef LOWDOWN_CONSOLIDATED_OFLAGS
         .oflags = LOWDOWN_NOLINK,

meson.build

@@ -376,12 +376,7 @@ curl = dependency('libcurl', 'curl', required : true, include_type : 'system')
 
 editline = dependency('libeditline', 'editline', version : '>=1.14', required : true, include_type : 'system')
 
-lowdown = dependency('lowdown', version : '>=0.9.0', required : true, include_type : 'system')
-
-# TODO(sterni): drop the corresponding #ifdef after NixOS 25.05 is EOL which still distributes lowdown < 1.4.0
-if lowdown.version().version_compare('>= 1.4.0')
-  add_project_arguments('-DLOWDOWN_SEPARATE_TERM_OPTS', language: 'cpp')
-endif
+lowdown = dependency('lowdown', version : '>=1.4.0', required : true, include_type : 'system')
 
 # TODO(sterni): drop the corresponding #ifdef after NixOS 25.11 is EOL which still distributes lowdown < 3.0.0
 if lowdown.version().version_compare('>= 3.0.0')