From 950a9cdd97a64e35ef2b794a393fbab648f07f6f Mon Sep 17 00:00:00 2001
From: Kurt <kurt.w.jung@gmail.com>
Date: Tue, 19 Nov 2019 09:42:17 -0500
Subject: [PATCH] Merge benoitkugler's modification time pull request

---
 def.go                      |  3 ++-
 fpdf.go                     | 34 +++++++++++++++++++++++++++-------
 fpdf_test.go                | 17 +++++++++++++++++
 internal/example/example.go |  1 +
 4 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/def.go b/def.go
index 20c0ea30..6a7030f9 100644
--- a/def.go
+++ b/def.go
@@ -573,7 +573,8 @@ type Fpdf struct {
 	author           string                     // author
 	keywords         string                     // keywords
 	creator          string                     // creator
-	creationDate     time.Time                  // override for dcoument CreationDate value
+	creationDate     time.Time                  // override for document CreationDate value
+	modDate          time.Time                  // override for document ModDate value
 	aliasNbPagesStr  string                     // alias for total number of pages
 	pdfVersion       string                     // PDF version number
 	fontDirStr       string                     // location of font definition files
diff --git a/fpdf.go b/fpdf.go
index 2d910583..46651cbb 100644
--- a/fpdf.go
+++ b/fpdf.go
@@ -46,6 +46,7 @@ var gl struct {
 	catalogSort  bool
 	noCompress   bool // Initial zero value indicates compression
 	creationDate time.Time
+	modDate      time.Time
 }
 
 type fmtBuffer struct {
@@ -205,6 +206,7 @@ func fpdfNew(orientationStr, unitStr, sizeStr, fontDirStr string, size SizeType)
 	f.layerInit()
 	f.catalogSort = gl.catalogSort
 	f.creationDate = gl.creationDate
+	f.modDate = gl.modDate
 	f.userUnderlineThickness = 1
 	return
 }
@@ -3810,6 +3812,13 @@ func SetDefaultCreationDate(tm time.Time) {
 	gl.creationDate = tm
 }
 
+// SetDefaultModificationDate sets the default value of the document modification date
+// that will be used when initializing a new Fpdf instance. See
+// SetCreationDate() for more details.
+func SetDefaultModificationDate(tm time.Time) {
+	gl.modDate = tm
+}
+
 // SetCreationDate fixes the document's internal CreationDate value. By
 // default, the time when the document is generated is used for this value.
 // This method is typically only used for testing purposes to facilitate PDF
@@ -3818,6 +3827,12 @@ func (f *Fpdf) SetCreationDate(tm time.Time) {
 	f.creationDate = tm
 }
 
+// SetModificationDate fixes the document's internal ModDate value.
+// See `SetCreationDate` for more details.
+func (f *Fpdf) SetModificationDate(tm time.Time) {
+	f.modDate = tm
+}
+
 // SetJavascript adds Adobe JavaScript to the document.
 func (f *Fpdf) SetJavascript(script string) {
 	f.javascript = &script
@@ -4595,8 +4610,15 @@ func (f *Fpdf) putresources() {
 	return
 }
 
+// returns Now() if tm is zero
+func timeOrNow(tm time.Time) time.Time {
+	if tm.IsZero() {
+		return time.Now()
+	}
+	return tm
+}
+
 func (f *Fpdf) putinfo() {
-	var tm time.Time
 	if len(f.producer) > 0 {
 		f.outf("/Producer %s", f.textstring(f.producer))
 	}
@@ -4615,12 +4637,10 @@ func (f *Fpdf) putinfo() {
 	if len(f.creator) > 0 {
 		f.outf("/Creator %s", f.textstring(f.creator))
 	}
-	if f.creationDate.IsZero() {
-		tm = time.Now()
-	} else {
-		tm = f.creationDate
-	}
-	f.outf("/CreationDate %s", f.textstring("D:"+tm.Format("20060102150405")))
+	creation := timeOrNow(f.creationDate)
+	f.outf("/CreationDate %s", f.textstring("D:"+creation.Format("20060102150405")))
+	mod := timeOrNow(f.modDate)
+	f.outf("/ModDate %s", f.textstring("D:"+mod.Format("20060102150405")))
 }
 
 func (f *Fpdf) putcatalog() {
diff --git a/fpdf_test.go b/fpdf_test.go
index bd0ef1d5..2cf1d1fc 100644
--- a/fpdf_test.go
+++ b/fpdf_test.go
@@ -2377,6 +2377,7 @@ func ExampleFpdf_SetPageBox() {
 	// ~ pdfinfo -box pdf/Fpdf_PageBox.pdf
 	// Producer:       FPDF 1.7
 	// CreationDate:   Sat Jan  1 00:00:00 2000
+	// ModDate:   	   Sat Jan  1 00:00:00 2000
 	// Tagged:         no
 	// Form:           none
 	// Pages:          1
@@ -2886,3 +2887,19 @@ func ExampleFpdf_AddAttachmentAnnotation() {
 	// Output:
 	// Successfully generated pdf/Fpdf_FileAnnotations.pdf
 }
+
+func ExampleFpdf_SetModificationDate() {
+	// pdfinfo (from http://www.xpdfreader.com) reports the following for this example :
+	// ~ pdfinfo -box pdf/Fpdf_PageBox.pdf
+	// Producer:       FPDF 1.7
+	// CreationDate:   Sat Jan  1 00:00:00 2000
+	// ModDate:        Sun Jan  2 10:22:30 2000
+	pdf := gofpdf.New("", "", "", "")
+	pdf.AddPage()
+	pdf.SetModificationDate(time.Date(2000, 1, 2, 10, 22, 30, 0, time.UTC))
+	fileStr := example.Filename("Fpdf_SetModificationDate")
+	err := pdf.OutputFileAndClose(fileStr)
+	example.Summary(err, fileStr)
+	// Output:
+	// Successfully generated pdf/Fpdf_SetModificationDate.pdf
+}
diff --git a/internal/example/example.go b/internal/example/example.go
index e9eb2a35..2667c4d1 100644
--- a/internal/example/example.go
+++ b/internal/example/example.go
@@ -34,6 +34,7 @@ func init() {
 	gofpdf.SetDefaultCompression(false)
 	gofpdf.SetDefaultCatalogSort(true)
 	gofpdf.SetDefaultCreationDate(time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC))
+	gofpdf.SetDefaultModificationDate(time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC))
 }
 
 // setRoot assigns the relative path to the gofpdfDir directory based on current working