Revert "Fix bug #64865: Use CONTEXT_DOCUMENT_ROOT for scanning dir tree"

This reverts commit 98bfad7.

This doesn't work well in some setups, see bug #80113 and GH-5051.
Reverting this for now.

NEWS

@@ -239,8 +239,6 @@ PHP                                                                        NEWS
   . Use libenchant-2 when available.
 
 - FPM:
-  . Fixed bug #64865 (Search for .user.ini files from script dir up to
-    CONTEXT_DOCUMENT_ROOT). (Will Bender)
   . Add pm.status_listen option. (Jakub Zelenka)
 
 - GD:

UPGRADING

@@ -845,10 +845,6 @@ PHP 8.0 UPGRADE NOTES
 - Apache:
   . The PHP module has been renamed from php7_module to php_module.
 
-- CGI and FPM will now use CONTEXT_DOCUMENT_ROOT to scan for .user.ini files,
-  if it is defined. Otherwise, DOCUMENT_ROOT will be used as before. This
-  improves support for Apache mod_userdir and mod_alias.
-
 ========================================
 4. Deprecated Functionality
 ========================================

sapi/cgi/cgi_main.c

@@ -914,12 +914,9 @@ static int sapi_cgi_activate(void)
 			if (fcgi_is_fastcgi()) {
 				fcgi_request *request = (fcgi_request*) SG(server_context);
 
-				/* Prefer CONTEXT_DOCUMENT_ROOT if set */
-				doc_root = FCGI_GETENV(request, "CONTEXT_DOCUMENT_ROOT");
-				doc_root = doc_root ? doc_root : FCGI_GETENV(request, "DOCUMENT_ROOT");
+				doc_root = FCGI_GETENV(request, "DOCUMENT_ROOT");
 			} else {
-				doc_root = getenv("CONTEXT_DOCUMENT_ROOT");
-				doc_root = doc_root ? doc_root : getenv("DOCUMENT_ROOT");
+				doc_root = getenv("DOCUMENT_ROOT");
 			}
 			/* DOCUMENT_ROOT should also be defined at this stage..but better check it anyway */
 			if (doc_root) {

sapi/fpm/fpm/fpm_main.c

@@ -729,10 +729,7 @@ static int sapi_cgi_activate(void) /* {{{ */
 
 		/* Load and activate user ini files in path starting from DOCUMENT_ROOT */
 		if (PG(user_ini_filename) && *PG(user_ini_filename)) {
-			/* Prefer CONTEXT_DOCUMENT_ROOT if set */
-			doc_root = FCGI_GETENV(request, "CONTEXT_DOCUMENT_ROOT");
-			doc_root = doc_root ? doc_root : FCGI_GETENV(request, "DOCUMENT_ROOT");
-
+			doc_root = FCGI_GETENV(request, "DOCUMENT_ROOT");
 			/* DOCUMENT_ROOT should also be defined at this stage..but better check it anyway */
 			if (doc_root) {
 				doc_root_len = strlen(doc_root);