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Go: avoid non-deterministic output 

The code has even turned out simpler.
This commit is contained in:
Přemysl Eric Janouch 2020-09-06 04:38:41 +02:00
parent 8913f8ba9c
commit af6a937033
Signed by: p
GPG Key ID: A0420B94F92B9493
1 changed files with 16 additions and 20 deletions
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36
pdf/pdf.go
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@ -853,30 +853,19 @@ func (u *Updater) FlushUpdates() {
return updated[i] < updated[j]
})
groups := make(map[uint]uint)
for i := 0; i < len(updated); {
start, count := updated[i], uint(1)
for i++; i != len(updated) && updated[i] == start+count; i++ {
count++
}
groups[start] = count
}
// Taking literally "Each cross-reference section begins with a line
// containing the keyword xref. Following this line are one or more
// cross-reference subsections." from 3.4.3 in PDF Reference.
if len(groups) == 0 {
groups[0] = 0
}
buf := bytes.NewBuffer(u.Document)
startXref := buf.Len() + 1
buf.WriteString("\nxref\n")
for start, count := range groups {
fmt.Fprintf(buf, "%d %d\n", start, count)
for i := uint(0); i < count; i++ {
ref := u.xref[start+uint(i)]
for i := 0; i < len(updated); {
start, stop := updated[i], updated[i]+1
for i++; i < len(updated) && updated[i] == stop; i++ {
stop++
}
fmt.Fprintf(buf, "%d %d\n", start, stop-start)
for ; start < stop; start++ {
ref := u.xref[start]
if ref.nonfree {
fmt.Fprintf(buf, "%010d %05d n \n", ref.offset, ref.generation)
} else {
@ -885,6 +874,13 @@ func (u *Updater) FlushUpdates() {
}
}
// Taking literally "Each cross-reference section begins with a line
// containing the keyword xref. Following this line are one or more
// cross-reference subsections." from 3.4.3 in PDF Reference.
if len(updated) == 0 {
fmt.Fprintf(buf, "%d %d\n", 0, 0)
}
u.Trailer["Size"] = NewNumeric(float64(u.xrefSize))
trailer := NewDict(u.Trailer)