Currently, scanner uses -1 to represent 2 different states:
1. I haven't yet scanned anything, call it "Beginning of File"
2. I've reached the end of the input, ie EOF
The result of this behavior is that calling Peek() when next()
has detected the end of the input and set s.ch to scanner.EOF,
is that Peek() things "oh, s.ch is < 0, which to me means that
I haven't scanned any next yet, let me try and clear the BOM
marker."
When this behavior is run on a typical IO, next() will issue
a Read and get (0, io.EOF) back for the second time without
blocking and Peek() will return scanner.EOF.
The bug comes into play when, inside a terminal, hitting Control-D.
This causes the terminal to return a EOF condition to the reader
but it does not actually close the fd.
So, combining these 2 situations, we arrive at the bug:
What is expected: hitting Control-D in a terminal will make Peek()
return scanner.EOF instantly.
What actually happens:
0. Code waiting in Next()
1. User hits Control-D
2. fd returns EOF condition
3. EOF bubbles it's way out to line 249 in scanner.go
4. next() returns scanner.EOF
5. Next() saves the scanner.EOF to s.ch and returns the previous value
6. Peek() runs, sees s.ch < 0, mistakenly thinks it hasn't run yet and
tries to read the BOM marker.
7. next() sees the buffer is empty and tries to fill it again, blocking
on line 249.
The fix is simple: use a different code to indicate that no data
has been scanned.
Change-Id: Iee8f4da5881682c4d4c36b93b9bf397ac5798179
Reviewed-on: https://go-review.googlesource.com/7913
Reviewed-by: Robert Griesemer <gri@golang.org>
text/template turned this into an error but html/template crashed.
Refactor text/template.Execute to export a new function,
text/template.DefinedTemplates, so html/template can get the same
helpful error message in this case, and invoke it when there is no
definition for a template being escaped.
Fixes#10204.
Change-Id: I1d04e9e7ebca829bc08509caeb65e75da969711f
Reviewed-on: https://go-review.googlesource.com/7855
Reviewed-by: Russ Cox <rsc@golang.org>
An explicit nil in an expression like nil.Foo caused a panic
because the evaluator attempted to reflect on the nil.
A typeless nil like this cannot be used to do anything, so
just error out.
Fixes#9426
Change-Id: Icd2c9c7533dda742748bf161eced163991a12f54
Reviewed-on: https://go-review.googlesource.com/7643
Reviewed-by: David Symonds <dsymonds@golang.org>
Simple bug in argument processing: The final arg may
be the pipeline value, in which case it gets bound to the
fixed argument section. The code got that wrong. Easy
to fix.
Fixes#8950.
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/161750043
Was just a missing case (literally) in the type checker.
Fixes#8473.
LGTM=adg
R=golang-codereviews, adg
CC=golang-codereviews
https://golang.org/cl/142460043
Previously, signed and unsigned integers could not be compared, but
this has problems with things like comparing 'x' with a byte in a string.
Since signed and unsigned integers have a well-defined ordering,
even though their types are different, and since we already allow
comparison regardless of the size of the integers, why not allow it
regardless of the sign?
Integers only, a fine place to draw the line.
Fixes#7489.
LGTM=adg
R=golang-codereviews, adg
CC=golang-codereviews
https://golang.org/cl/149780043
