RFR: 8282008: Incorrect handling of quoted arguments in ProcessBuilder [v4]

[Olga Mikhaltsova]

> This fix made equal processing of strings such as ""C:\\Program Files\\Git\\"" before and after JDK-8250568.
> 
> For example, it's needed to execute the following command on Windows:
> `C:\Windows\SysWOW64\WScript.exe "MyVB.vbs" "C:\Program Files\Git" "Test"`
> it's equal to:
> `new ProcessBuilder("C:\\Windows\\SysWOW64\\WScript.exe", "MyVB.vbs", ""C:\\Program Files\\Git\\"", "Test").start();`
> 
> While processing, the 3rd argument ""C:\\Program Files\\Git\\"" treated as unquoted due to the condition added in JDK-8250568.
> 
>     private static String unQuote(String str) {
>     .. 
>        if (str.endsWith("\\"")) {
>             return str;    // not properly quoted, treat as unquoted
>         }
>     ..
>     }
> 
> 
> that leads to the additional surrounding by quotes in ProcessImpl::createCommandLine(..) because needsEscaping(..) returns true due to the space inside the string argument.
> As a result the native function CreateProcessW (src/java.base/windows/native/libjava/ProcessImpl_md.c) gets the incorrectly quoted argument: 
> 
> pcmd = C:\Windows\SysWOW64\WScript.exe MyVB.vbs ""C:\Program Files\Git"" Test
> (jdk.lang.Process.allowAmbiguousCommands = true)
> pcmd = "C:\Windows\SysWOW64\WScript.exe" MyVB.vbs ""C:\Program Files\Git\\"" Test
> (jdk.lang.Process.allowAmbiguousCommands = false)
> 
> 
> Obviously, a string ending with `"\\""` must not be started with `"""` to treat as unquoted overwise it’s should be treated as properly quoted.

Olga Mikhaltsova has updated the pull request incrementally with one additional commit since the last revision:

  Reverted addition of the test via echo

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7504/files
  - new: https://git.openjdk.java.net/jdk/pull/7504/files/0eceecac..8cbdfe77

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7504&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7504&range=02-03

  Stats: 89 lines in 1 file changed: 0 ins; 89 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7504.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7504/head:pull/7504

PR: https://git.openjdk.java.net/jdk/pull/7504