line&bar chart subtitles are always sanitized

This obviates bug 726449 for consistency

gnucash/report/report-system/html-barchart.scm

@@ -135,24 +135,6 @@
 (define gnc:html-barchart-subtitle
   (record-accessor <html-barchart> 'subtitle))
 
-;; Note: Due to Bug726449 the input string's non-printable control
-;;       characters must translated to HTML format tags BEFORE
-;;       or WHEN calling this function.
-;;       AND:
-;;       To ensure that the generated subtitle doesn't contain any
-;;       unescaped quotes or backslashes, all strings must be freed
-;;       from those by calling gnc:html-string-sanitize.
-;;       Otherwise we're opening the gates again for bug 721768.
-;;
-;;       Example: "\n" must be translated to "<br /> to introduce
-;;                a line break into the chart subtitle.
-;;
-;;       Example call:
-;;         (gnc:html-barchart-set-subtitle! chart
-;;           (string-append "Bgt:"
-;;                          (gnc:html-string-sanitize (number->string bgt-sum))
-;;                          "<br /> Act:" ;; line break in the chart sub-title
-;;                          (gnc:html-string-sanitize (number->string act-sum))))
 (define gnc:html-barchart-set-subtitle!
   (record-modifier <html-barchart> 'subtitle))
 

gnucash/report/report-system/html-scatter.scm

@@ -205,14 +205,12 @@
                 };\n")
 
             (if title
-              (begin
-                (push "  options.title = \"")
-                (push title) (push "\";\n")))
+                (push (format #f "  options.title = ~s;\n"
+                              (gnc:html-string-sanitize title))))
 
             (if subtitle
-              (begin
-                (push "  options.title += \" (")
-                (push subtitle) (push ")\";\n")))
+                (push (format #f "  options.title += ' (' + ~s + ')';\n"
+                              (gnc:html-string-sanitize subtitle))))
 
             (if (and (string? x-label) (> (string-length x-label) 0))
               (begin

gnucash/report/standard-reports/budget-barchart.scm

@@ -237,14 +237,8 @@
           (gnc:html-barchart-append-column! chart act-vals)
           (gnc:html-barchart-set-row-labels! chart date-iso-string-list)
           (if running-sum
-            (gnc:html-barchart-set-subtitle! chart
-              (string-append "Bgt:"
-                         (gnc:html-string-sanitize (number->string bgt-sum))
-                         "<br /> Act:"
-                         (gnc:html-string-sanitize (number->string act-sum))
-              )
-            )
-          )
+              (gnc:html-barchart-set-subtitle!
+               chart (format #f "Bgt: ~a Act: ~a" bgt-sum act-sum)))
         )
         ;; else
         (begin
@@ -253,14 +247,9 @@
           (gnc:html-linechart-append-column! chart act-vals)
           (gnc:html-linechart-set-row-labels! chart date-iso-string-list)
           (if running-sum
-            (gnc:html-linechart-set-subtitle! chart
-              (string-append "Bgt:"
-                         (gnc:html-string-sanitize (number->string bgt-sum))
-                         "<br /> Act:"
-                         (gnc:html-string-sanitize (number->string act-sum))
-              )
-            )
-          )
+              (gnc:html-linechart-set-subtitle!
+               chart
+               (format #f "Bgt: ~a Act: ~a" bgt-sum act-sum)))
         )
       )
     )