From dbc0fa9bd6831ea060df410b70de32627c5c1f68 Mon Sep 17 00:00:00 2001
From: Raphael <glephunter@gmail.com>
Date: Wed, 3 Apr 2024 18:44:57 +0800
Subject: [PATCH] fix(stdpath): remove duplicate directories (#26653)

---
 src/nvim/os/stdpaths.c                    | 47 +++++++++++++++++++++++
 test/functional/options/defaults_spec.lua | 16 ++++----
 2 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/src/nvim/os/stdpaths.c b/src/nvim/os/stdpaths.c
index ede17bc7c8..187a0e0674 100644
--- a/src/nvim/os/stdpaths.c
+++ b/src/nvim/os/stdpaths.c
@@ -2,13 +2,16 @@
 #include <stdbool.h>
 #include <string.h>
 
+#include "klib/kvec.h"
 #include "nvim/ascii_defs.h"
 #include "nvim/fileio.h"
 #include "nvim/globals.h"
 #include "nvim/memory.h"
 #include "nvim/os/os.h"
+#include "nvim/os/os_defs.h"
 #include "nvim/os/stdpaths_defs.h"
 #include "nvim/path.h"
+#include "nvim/strings.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "os/stdpaths.c.generated.h"
@@ -93,6 +96,46 @@ bool appname_is_valid(void)
   return true;
 }
 
+/// Remove duplicate directories in the given XDG directory.
+/// @param[in]  List of directories possibly with duplicates
+/// @param[out]  List of directories without duplicates
+static char *xdg_remove_duplicate(char *ret, const char *sep)
+{
+  kvec_t(char *) data = KV_INITIAL_VALUE;
+  char *saveptr;
+
+  char *token = os_strtok(ret, sep, &saveptr);
+  while (token != NULL) {
+    // Check if the directory is not already in the list
+    bool is_duplicate = false;
+    for (size_t i = 0; i < data.size; i++) {
+      if (path_fnamecmp(kv_A(data, i), token) == 0) {
+        is_duplicate = true;
+        break;
+      }
+    }
+    // If it's not a duplicate, add it to the list
+    if (!is_duplicate) {
+      kv_push(data, token);
+    }
+    token = os_strtok(NULL, sep, &saveptr);
+  }
+
+  StringBuilder result = KV_INITIAL_VALUE;
+
+  for (size_t i = 0; i < data.size; i++) {
+    if (i == 0) {
+      kv_printf(result, "%s", kv_A(data, i));
+    } else {
+      kv_printf(result, "%s%s", sep, kv_A(data, i));
+    }
+  }
+
+  kv_destroy(data);
+  xfree(ret);
+  return result.items;
+}
+
 /// Return XDG variable value
 ///
 /// @param[in]  idx  XDG variable to use.
@@ -131,6 +174,10 @@ char *stdpaths_get_xdg_var(const XDGVarType idx)
     ret = xmemdupz(ret, len >= 2 ? len - 1 : 0);  // Trim trailing slash.
   }
 
+  if ((idx == kXDGDataDirs || idx == kXDGConfigDirs) && ret != NULL) {
+    ret = xdg_remove_duplicate(ret, ENV_SEPSTR);
+  }
+
   return ret;
 }
 
diff --git a/test/functional/options/defaults_spec.lua b/test/functional/options/defaults_spec.lua
index 2d3d827619..5e98453565 100644
--- a/test/functional/options/defaults_spec.lua
+++ b/test/functional/options/defaults_spec.lua
@@ -378,7 +378,7 @@ describe('XDG defaults', function()
             .. root_path
             .. ('/b'):rep(2048)
             .. '/nvim'
-            .. (',' .. root_path .. '/c/nvim'):rep(512)
+            .. (',' .. root_path .. '/c/nvim')
             .. ','
             .. root_path
             .. ('/X'):rep(4096)
@@ -393,12 +393,12 @@ describe('XDG defaults', function()
             .. root_path
             .. ('/B'):rep(2048)
             .. '/nvim/site'
-            .. (',' .. root_path .. '/C/nvim/site'):rep(512)
+            .. (',' .. root_path .. '/C/nvim/site')
             .. ','
             .. vimruntime
             .. ','
             .. libdir
-            .. (',' .. root_path .. '/C/nvim/site/after'):rep(512)
+            .. (',' .. root_path .. '/C/nvim/site/after')
             .. ','
             .. root_path
             .. ('/B'):rep(2048)
@@ -413,7 +413,7 @@ describe('XDG defaults', function()
             .. '/'
             .. data_dir
             .. '/site/after'
-            .. (',' .. root_path .. '/c/nvim/after'):rep(512)
+            .. (',' .. root_path .. '/c/nvim/after')
             .. ','
             .. root_path
             .. ('/b'):rep(2048)
@@ -449,7 +449,7 @@ describe('XDG defaults', function()
             .. root_path
             .. ('/b'):rep(2048)
             .. '/nvim'
-            .. (',' .. root_path .. '/c/nvim'):rep(512)
+            .. (',' .. root_path .. '/c/nvim')
             .. ','
             .. root_path
             .. ('/X'):rep(4096)
@@ -464,12 +464,12 @@ describe('XDG defaults', function()
             .. root_path
             .. ('/B'):rep(2048)
             .. '/nvim/site'
-            .. (',' .. root_path .. '/C/nvim/site'):rep(512)
+            .. (',' .. root_path .. '/C/nvim/site')
             .. ','
             .. vimruntime
             .. ','
             .. libdir
-            .. (',' .. root_path .. '/C/nvim/site/after'):rep(512)
+            .. (',' .. root_path .. '/C/nvim/site/after')
             .. ','
             .. root_path
             .. ('/B'):rep(2048)
@@ -484,7 +484,7 @@ describe('XDG defaults', function()
             .. '/'
             .. data_dir
             .. '/site/after'
-            .. (',' .. root_path .. '/c/nvim/after'):rep(512)
+            .. (',' .. root_path .. '/c/nvim/after')
             .. ','
             .. root_path
             .. ('/b'):rep(2048)