s3api: Fix response-content-disposition query parameter not being honored

Fixes #7486

This fix resolves an issue where S3 presigned URLs with query parameters
like `response-content-disposition`, `response-content-type`, etc. were
being ignored, causing browsers to use default file handling instead of
the specified behavior.

Changes:
- Modified `setResponseHeaders()` to accept the HTTP request object
- Added logic to process S3 passthrough headers from query parameters
- Updated all call sites to pass the request object
- Supports all AWS S3 response override parameters:
  - response-content-disposition
  - response-content-type
  - response-cache-control
  - response-content-encoding
  - response-content-language
  - response-expires

The implementation follows the same pattern used in the filer handler
and properly honors the AWS S3 API specification for presigned URLs.

Testing:
- Existing S3 API tests pass without modification
- Build succeeds with no compilation errors

weed/s3api/s3api_object_handlers.go

@@ -880,7 +880,7 @@ func (s3a *S3ApiServer) streamFromVolumeServers(w http.ResponseWriter, r *http.R
 				return newStreamErrorWithResponse(fmt.Errorf("invalid range for inline content: start=%d, end=%d, len=%d", start, end, len(entry.Content)))
 			}
 			// Validation passed - now set headers and write
-			s3a.setResponseHeaders(w, entry, totalSize)
+			s3a.setResponseHeaders(w, r, entry, totalSize)
 			w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", offset, offset+size-1, totalSize))
 			w.Header().Set("Content-Length", strconv.FormatInt(size, 10))
 			w.WriteHeader(http.StatusPartialContent)
@@ -888,7 +888,7 @@ func (s3a *S3ApiServer) streamFromVolumeServers(w http.ResponseWriter, r *http.R
 			return err
 		}
 		// Non-range request for inline content
-		s3a.setResponseHeaders(w, entry, totalSize)
+		s3a.setResponseHeaders(w, r, entry, totalSize)
 		w.WriteHeader(http.StatusOK)
 		_, err := w.Write(entry.Content)
 		return err
@@ -908,7 +908,7 @@ func (s3a *S3ApiServer) streamFromVolumeServers(w http.ResponseWriter, r *http.R
 			return newStreamErrorWithResponse(fmt.Errorf("data integrity error: size %d reported but no content available", totalSize))
 		}
 		// Empty object - set headers and write status
-		s3a.setResponseHeaders(w, entry, totalSize)
+		s3a.setResponseHeaders(w, r, entry, totalSize)
 		w.WriteHeader(http.StatusOK)
 		return nil
 	}
@@ -958,7 +958,7 @@ func (s3a *S3ApiServer) streamFromVolumeServers(w http.ResponseWriter, r *http.R
 
 	// All validation and preparation successful - NOW set headers and write status
 	tHeaderSet := time.Now()
-	s3a.setResponseHeaders(w, entry, totalSize)
+	s3a.setResponseHeaders(w, r, entry, totalSize)
 
 	// Override/add range-specific headers if this is a range request
 	if isRangeRequest {
@@ -1164,7 +1164,7 @@ func (s3a *S3ApiServer) streamFromVolumeServersWithSSE(w http.ResponseWriter, r
 	// Set response headers
 	// IMPORTANT: Set ALL headers BEFORE calling WriteHeader (headers are ignored after WriteHeader)
 	tHeaderSet := time.Now()
-	s3a.setResponseHeaders(w, entry, totalSize)
+	s3a.setResponseHeaders(w, r, entry, totalSize)
 	s3a.addSSEResponseHeadersFromEntry(w, r, entry, sseType)
 
 	// Override/add range-specific headers if this is a range request
@@ -1894,7 +1894,7 @@ func (s3a *S3ApiServer) addSSEResponseHeadersFromEntry(w http.ResponseWriter, r
 }
 
 // setResponseHeaders sets all standard HTTP response headers from entry metadata
-func (s3a *S3ApiServer) setResponseHeaders(w http.ResponseWriter, entry *filer_pb.Entry, totalSize int64) {
+func (s3a *S3ApiServer) setResponseHeaders(w http.ResponseWriter, r *http.Request, entry *filer_pb.Entry, totalSize int64) {
 	// Safety check: entry must be valid
 	if entry == nil {
 		glog.Errorf("setResponseHeaders: entry is nil")
@@ -1974,6 +1974,18 @@ func (s3a *S3ApiServer) setResponseHeaders(w http.ResponseWriter, entry *filer_p
 			w.Header().Set(s3_constants.AmzTagCount, strconv.Itoa(tagCount))
 		}
 	}
+
+	// Apply S3 passthrough headers from query parameters
+	// AWS S3 supports overriding response headers via query parameters like:
+	// ?response-cache-control=no-cache&response-content-type=application/json
+	// This allows presigned URLs to control how browsers handle the downloaded content
+	if r != nil {
+		for queryParam, headerValue := range r.URL.Query() {
+			if normalizedHeader, ok := s3_constants.PassThroughHeaders[strings.ToLower(queryParam)]; ok && len(headerValue) > 0 {
+				w.Header().Set(normalizedHeader, headerValue[0])
+			}
+		}
+	}
 }
 
 // simpleMasterClient implements the minimal interface for streaming
@@ -2241,7 +2253,7 @@ func (s3a *S3ApiServer) HeadObjectHandler(w http.ResponseWriter, r *http.Request
 
 	// For HEAD requests, we already have all metadata - just set headers directly
 	totalSize := int64(filer.FileSize(objectEntryForSSE))
-	s3a.setResponseHeaders(w, objectEntryForSSE, totalSize)
+	s3a.setResponseHeaders(w, r, objectEntryForSSE, totalSize)
 
 	// Check if PartNumber query parameter is present (for multipart objects)
 	// This logic matches the filer handler for consistency