Add bash shell function to make python work like it should.

This uses the virtual /proc filesystem to identify when the user runs
`python` without redirecting stdout/stdin. If this is the case, we run
`python -i` instead. Otherwise, or if there are arguments, we run it
verbatim.

R=dnj@chromium.org
BUG=598956

Review URL: https://codereview.chromium.org/1851113003 .

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@299681 0039d316-1c4b-4281-b951-d872f2087c98

bootstrap/win/profile.d.python.sh

+#!/bin/bash
+# This alias allows invocations of `python` to work as expected under msys bash.
+# In particular, it detects if stdout+stdin are both attached to a pseudo-tty,
+# and if so, invokes python in interactive mode. If this is not the case, or
+# the user passes any arguments, python will be invoked unmodified.
+python() {
+  if [[ $# > 0 ]]; then
+    python.exe "$@"
+  else
+    readlink /proc/$$/fd/0 | grep pty > /dev/null
+    TTY0=$?
+    readlink /proc/$$/fd/1 | grep pty > /dev/null
+    TTY1=$?
+    if [ $TTY0 == 0 ] && [ $TTY1 == 0 ]; then
+      python.exe -i
+    else
+      python.exe
+    fi
+  fi
+}

bootstrap/win/win_tools.bat

@@ -100,6 +100,7 @@ for %%f in (git.bat gitk.bat ssh.bat ssh-keygen.bat git-bash) do (
   %FIND_EXE% "%GIT_BIN_DIR%" "%WIN_TOOLS_ROOT_DIR%\%%f" 2>nul 1>nul
   if errorlevel 1 goto :GIT_MAKE_BATCH_FILES
 )
+if not exist %GIT_INST_DIR%\etc\profile.d\python.sh goto :GIT_MAKE_BATCH_FILES
 goto :SYNC_GIT_HELP_FILES
 
 :GIT_INSTALL
@@ -138,6 +139,7 @@ call "%SED%" -e "s/GIT_BIN_DIR/%GIT_BIN_DIR%/g" -e "s/GIT_PROGRAM/cmd\\\\gitk.ex
 call "%SED%" -e "s/GIT_BIN_DIR/%GIT_BIN_DIR%/g" -e "s/GIT_PROGRAM/usr\\\\bin\\\\ssh.exe/g" < %GIT_TEMPL% > "%WIN_TOOLS_ROOT_DIR%\ssh.bat"
 call "%SED%" -e "s/GIT_BIN_DIR/%GIT_BIN_DIR%/g" -e "s/GIT_PROGRAM/usr\\\\bin\\\\ssh-keygen.exe/g" < %GIT_TEMPL% > "%WIN_TOOLS_ROOT_DIR%\ssh-keygen.bat"
 call "%SED%" -e "s/GIT_BIN_DIR/%GIT_BIN_DIR%/g" -e "s/PYTHON_BIN_DIR/python276_bin/g" -e "s/SVN_BIN_DIR/svn_bin/g" < %~dp0git-bash.template.sh > "%WIN_TOOLS_ROOT_DIR%\git-bash"
+copy "%~dp0profile.d.python.sh" %GIT_INST_DIR%\etc\profile.d\python.sh > NUL
 
 :: Ensure various git configurations are set correctly at they system level.
 call "%WIN_TOOLS_ROOT_DIR%\git.bat" config --system core.autocrlf false