fix(custom-fields): address code review findings

- API: return 500 on GetCustomFieldsByOwner failure instead of silently
  swallowing the error
- resolveExtensionMetadata: add DownloadGating/KeyPrefix to metadata
  struct instead of mutating the caller's cfg pointer (side effect)
- resolveExtensionMetadata: add Description custom field mapping
- Composer: use meta.PHPMinimum instead of bypassing the cascade
- Web form: flash error on custom field save failure instead of silent log

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

routers/api/v1/repo/issue.go

@@ -705,7 +705,11 @@ func CreateIssue(ctx *context.APIContext) {
 	// Save custom field values if provided (resolve field names to IDs).
 	if len(form.CustomFields) > 0 {
 		defs, defErr := issues_model.GetCustomFieldsByOwner(ctx, ctx.Repo.Repository.OwnerID, issues_model.CustomFieldScopeIssue)
-		if defErr == nil && len(defs) > 0 {
+		if defErr != nil {
+			ctx.APIErrorInternal(defErr)
+			return
+		}
+		if len(defs) > 0 {
 			vals := make(map[int64]string)
 			for _, def := range defs {
 				if v, ok := form.CustomFields[def.Name]; ok {

routers/web/repo/issue_new.go

@@ -441,6 +441,7 @@ func saveCustomFieldsFromForm(ctx *context.Context, ownerID, issueID int64) {
 	if len(vals) > 0 {
 		if err := issues_model.SetCustomFieldValues(ctx, issueID, vals); err != nil {
 			log.Error("saveCustomFieldsFromForm: %v", err)
+			ctx.Flash.Error("Failed to save custom field values")
 		}
 	}
 }

services/updateserver/composer.go

@@ -87,8 +87,8 @@ func GenerateComposerJSON(ctx context.Context, repo *repo_model.Repository, lice
 	}
 
 	phpMin := ""
-	if cfg != nil && cfg.PHPMinimum != "" {
-		phpMin = ">=" + cfg.PHPMinimum
+	if meta.PHPMinimum != "" {
+		phpMin = ">=" + meta.PHPMinimum
 	}
 
 	streams := licenses.GetEffectiveStreams(ctx, repo.OwnerID, repo.ID)

services/updateserver/joomla.go

@@ -164,13 +164,15 @@ func NormalizeChannel(ch string) string {
 // extensionMetadata holds resolved metadata for feed generation.
 // Fields are resolved with priority: custom field → config table → default.
 type extensionMetadata struct {
-	Element       string
-	DisplayName   string
-	ExtType       string
-	TargetVersion string
-	PHPMinimum    string
-	Description   string
-	SupportURL    string
+	Element        string
+	DisplayName    string
+	ExtType        string
+	TargetVersion  string
+	PHPMinimum     string
+	Description    string
+	SupportURL     string
+	DownloadGating string
+	KeyPrefix      string
 }
 
 // resolveExtensionMetadata loads extension metadata with cascading fallback:
@@ -206,6 +208,12 @@ func resolveExtensionMetadata(ctx context.Context, repo *repo_model.Repository,
 		if cfg.SupportURL != "" {
 			m.SupportURL = cfg.SupportURL
 		}
+		if cfg.DownloadGating != "" {
+			m.DownloadGating = cfg.DownloadGating
+		}
+		if cfg.KeyPrefix != "" {
+			m.KeyPrefix = cfg.KeyPrefix
+		}
 	}
 
 	// Override with custom field values (highest priority).
@@ -244,11 +252,14 @@ func resolveExtensionMetadata(ctx context.Context, repo *repo_model.Repository,
 	if v := named["Support URL"]; v != "" {
 		m.SupportURL = v
 	}
-	if v := named["Download Gating"]; v != "" && cfg != nil {
-		cfg.DownloadGating = v
+	if v := named["Description"]; v != "" {
+		m.Description = v
 	}
-	if v := named["Key Prefix"]; v != "" && cfg != nil {
-		cfg.KeyPrefix = v
+	if v := named["Download Gating"]; v != "" {
+		m.DownloadGating = v
+	}
+	if v := named["Key Prefix"]; v != "" {
+		m.KeyPrefix = v
 	}
 
 	return m