fmt: check newline in the end of input
Sscanf doc says:
Newlines in the input must match newlines in the format.
However Sscanf didn't check newline in the end of input (EOF).
A test for the case is broken.
* check newline in EOF
* fix the test
* slightly simplify ss.doScanf
Fixes #12788
Change-Id: Iaf6b7d81324a72e557543ac22ecea5cecb72e0d6
Reviewed-on: https://go-review.googlesource.com/16165
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/fmt/scan.go b/src/fmt/scan.go
index 4618ed4..553deb4 100644
--- a/src/fmt/scan.go
+++ b/src/fmt/scan.go
@@ -1108,6 +1108,10 @@
// in the input.
inputc := s.getRune()
if inputc == eof {
+ if wasNewline {
+ // Newlines are mandatory.
+ return -1
+ }
return
}
if !isSpace(inputc) {
@@ -1148,17 +1152,18 @@
end := len(format) - 1
// We process one item per non-trivial format
for i := 0; i <= end; {
- w := s.advance(format[i:])
- if w > 0 {
+ switch w := s.advance(format[i:]); {
+ case w > 0:
i += w
continue
+ case w < 0:
+ // Can't advance format. Why not?
+ s.errorString("input does not match format")
}
- // Either we failed to advance, we have a percent character, or we ran out of input.
+
+ // Either we have a percent character, or we ran out of input.
+
if format[i] != '%' {
- // Can't advance format. Why not?
- if w < 0 {
- s.errorString("input does not match format")
- }
// Otherwise at EOF; "too many operands" error handled below
break
}
diff --git a/src/fmt/scan_test.go b/src/fmt/scan_test.go
index 7ac74dc..bcc2844 100644
--- a/src/fmt/scan_test.go
+++ b/src/fmt/scan_test.go
@@ -1114,14 +1114,22 @@
count int
ok bool
}{
- {"newline in both", "1\n2", "%d\n%d\n", 2, true},
+ {"newline in both", "1\n2", "%d\n%d", 2, true},
{"newline in input", "1\n2", "%d %d", 1, false},
+ {"extra newline in format", "1\n2", "%d\n%d\n", 2, false},
+ {"newline-newline in both", "1\n\n2", "%d\n\n%d", 2, true},
+ {"newline-newline in format", "1\n2", "%d\n\n%d", 1, false},
+ {"newline-newline in input", "1\n\n2", "%d\n%d", 1, false},
{"space-newline in input", "1 \n2", "%d %d", 1, false},
{"newline in format", "1 2", "%d\n%d", 1, false},
{"space-newline in format", "1 2", "%d \n%d", 1, false},
{"space-newline in both", "1 \n2", "%d \n%d", 2, true},
{"extra space in format", "1\n2", "%d\n %d", 2, true},
{"two extra spaces in format", "1\n2", "%d \n %d", 2, true},
+ {"newline start in both", "\n1 2", "\n%d %d", 2, true},
+ {"newline start in format", "1 2", "\n%d %d", 0, false},
+ {"newline start in input", "\n1 2", "%d %d", 0, false},
+ {"space-newline start in input", " \n1 2", "\n%d %d", 2, true},
}
for _, test := range tests {
n, err := Sscanf(test.text, test.format, &a, &b)
