feat: NVIM_APPNAME supports relative paths #25233

Problem:
NVIM_APPNAME does not allow path separators in the name, so relative
paths can't be used:

    NVIM_APPNAME="neovim-configs/first-config" nvim
    NVIM_APPNAME="neovim-configs/second-config" nvim

Solution:
Let NVIM_APPNAME be a relative path. Absolute paths are not supported.

fix #23056
fix #24966

1 files changed, 6 insertions, 1 deletions

diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index 7ff3e0ec6e..7609eb12b4 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -3279,12 +3279,18 @@ static void vim_mktempdir(void)
   char tmp[TEMP_FILE_PATH_MAXLEN];
   char path[TEMP_FILE_PATH_MAXLEN];
   char user[40] = { 0 };
+  char appname[40] = { 0 };
 
   (void)os_get_username(user, sizeof(user));
   // Usernames may contain slashes! #19240
   memchrsub(user, '/', '_', sizeof(user));
   memchrsub(user, '\\', '_', sizeof(user));
 
+  // Appname may be a relative path, replace slashes to make it name-like.
+  xstrlcpy(appname, get_appname(), sizeof(appname));
+  memchrsub(appname, '/', '%', sizeof(appname));
+  memchrsub(appname, '\\', '%', sizeof(appname));
+
   // Make sure the umask doesn't remove the executable bit.
   // "repl" has been reported to use "0177".
   mode_t umask_save = umask(0077);
@@ -3298,7 +3304,6 @@ static void vim_mktempdir(void)
     // "/tmp/" exists, now try to create "/tmp/nvim.<user>/".
     add_pathsep(tmp);
 
-    const char *appname = get_appname();
     xstrlcat(tmp, appname, sizeof(tmp));
     xstrlcat(tmp, ".", sizeof(tmp));
     xstrlcat(tmp, user, sizeof(tmp));