Ignore all environment variables with name starting with '='

Ignore all environment variables with name starting with '='

This will remove the Windows specific environment variables starting
with '=' from the environment. This also ignores the case where the
environment variable name is empty, which have been seen on Mac OS (reported
in the referenced bug).

BUG=http://dartbug.com/21961
R=lrn@google.com

Committed: https://code.google.com/p/dart/source/detail?r=42589

[Lasse Reichstein Nielsen, 2015-01-05 11:45:44]

lgtm

https://codereview.chromium.org/835863004/diff/1/sdk/lib/io/platform_impl.dart
File sdk/lib/io/platform_impl.dart (right):

https://codereview.chromium.org/835863004/diff/1/sdk/lib/io/platform_impl.dar...
sdk/lib/io/platform_impl.dart:61: // When running on Windows through cmd.exe
there are strange
Remove "strange". They are not strange, just ... misunderstood.

In CMD scripting, variables are "dynamic" environment variables which change
automatically. The values of the ones starting with "=" are reified in the
environment string of a new program (but, e.g., __CD__ isn't).

https://codereview.chromium.org/835863004/diff/1/sdk/lib/io/platform_impl.dar...
sdk/lib/io/platform_impl.dart:68: // On Mac OS an entry of just '=' has been
seen.
Add: Entries with no '=' should not happen. If it should happen, the entry is
ignored.

https://codereview.chromium.org/835863004/diff/1/sdk/lib/io/platform_impl.dar...
sdk/lib/io/platform_impl.dart:70: if (equalsIndex == 0 || equalsIndex == -1) {
equalsIndex <= 0
?

But switch the condition and avoid the continue:

if (equalsIndex > 0) {
  result[...] = ...;
}

[Søren Gjesse, 2015-01-05 12:32:14]

https://codereview.chromium.org/835863004/diff/1/sdk/lib/io/platform_impl.dart
File sdk/lib/io/platform_impl.dart (right):

https://codereview.chromium.org/835863004/diff/1/sdk/lib/io/platform_impl.dar...
sdk/lib/io/platform_impl.dart:61: // When running on Windows through cmd.exe
there are strange
On 2015/01/05 11:45:43, Lasse Reichstein Nielsen wrote:
> Remove "strange". They are not strange, just ... misunderstood.
> 
> In CMD scripting, variables are "dynamic" environment variables which change
> automatically. The values of the ones starting with "=" are reified in the
> environment string of a new program (but, e.g., __CD__ isn't).

Done.

https://codereview.chromium.org/835863004/diff/1/sdk/lib/io/platform_impl.dar...
sdk/lib/io/platform_impl.dart:68: // On Mac OS an entry of just '=' has been
seen.
On 2015/01/05 11:45:43, Lasse Reichstein Nielsen wrote:
> Add: Entries with no '=' should not happen. If it should happen, the entry is
> ignored.

Done.

https://codereview.chromium.org/835863004/diff/1/sdk/lib/io/platform_impl.dar...
sdk/lib/io/platform_impl.dart:70: if (equalsIndex == 0 || equalsIndex == -1) {
On 2015/01/05 11:45:43, Lasse Reichstein Nielsen wrote:
> equalsIndex <= 0
> ?
> 
> But switch the condition and avoid the continue:
> 
> if (equalsIndex > 0) {
>   result[...] = ...;
> }

Done.

[Søren Gjesse, 2015-01-05 12:37:49]

Committed patchset #2 (id:20001) manually as 42589 (presubmit successful).