Set MERMAID_MAX_SOURCE_CHARACTERS to 50000 (go-gitea#34152)

Fix go-gitea#32015

(cherry picked from commit f8edc29)

Author: wxiaoguang

custom/conf/app.example.ini

@@ -2444,7 +2444,7 @@ LEVEL = Info
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Set the maximum number of characters in a mermaid source. (Set to -1 to disable limits)
-;MERMAID_MAX_SOURCE_CHARACTERS = 5000
+;MERMAID_MAX_SOURCE_CHARACTERS = 50000
 ;; Set the maximum number of lines allowed for a filepreview. (Set to -1 to disable limits; set to 0 to disable the feature)
 ;FILEPREVIEW_MAX_LINES = 50
 

modules/setting/markup.go

@@ -62,7 +62,7 @@ type MarkupSanitizerRule struct {
 func loadMarkupFrom(rootCfg ConfigProvider) {
 	mustMapSetting(rootCfg, "markdown", &Markdown)
 
-	MermaidMaxSourceCharacters = rootCfg.Section("markup").Key("MERMAID_MAX_SOURCE_CHARACTERS").MustInt(5000)
+	MermaidMaxSourceCharacters = rootCfg.Section("markup").Key("MERMAID_MAX_SOURCE_CHARACTERS").MustInt(50000)
 	FilePreviewMaxLines = rootCfg.Section("markup").Key("FILEPREVIEW_MAX_LINES").MustInt(50)
 	ExternalMarkupRenderers = make([]*MarkupRenderer, 0, 10)
 	ExternalSanitizerRules = make([]MarkupSanitizerRule, 0, 10)