feat(caddy): use new first_exist_fallback try policy

caddy/caddy.go

@@ -529,6 +529,7 @@ func parsePhpServer(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error)
 	if indexFile != "off" {
 		dirRedir := false
 		dirIndex := "{http.request.uri.path}/" + indexFile
+		tryPolicy := "first_exist_fallback"
 
 		// if tryFiles wasn't overridden, use a reasonable default
 		if len(tryFiles) == 0 {
@@ -540,6 +541,11 @@ func parsePhpServer(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error)
 
 			dirRedir = true
 		} else {
+			if !strings.HasSuffix(tryFiles[len(tryFiles)-1], ".php") {
+				// use first_exist strategy if the last file is not a PHP file
+				tryPolicy = ""
+			}
+
 			for _, tf := range tryFiles {
 				if tf == dirIndex {
 					dirRedir = true
@@ -579,6 +585,7 @@ func parsePhpServer(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error)
 		rewriteMatcherSet := caddy.ModuleMap{
 			"file": h.JSON(fileserver.MatchFile{
 				TryFiles:  tryFiles,
+				TryPolicy: tryPolicy,
 				SplitPath: extensions,
 			}),
 		}