[2.7] remove hg support from patchcheck (GH-7440). (GH-7444)

(cherry picked from commit b8c0845)

Author: benjaminp

Tools/scripts/patchcheck.py

@@ -43,20 +43,6 @@ def call_fxn(*args, **kwargs):
     return decorated_fxn
 
 
-def mq_patches_applied():
-    """Check if there are any applied MQ patches."""
-    cmd = 'hg qapplied'
-    st = subprocess.Popen(cmd.split(),
-                          stdout=subprocess.PIPE,
-                          stderr=subprocess.PIPE)
-    try:
-        bstdout, _ = st.communicate()
-        return st.returncode == 0 and bstdout
-    finally:
-        st.stdout.close()
-        st.stderr.close()
-
-
 def get_git_branch():
     """Get the symbolic name for the current git branch"""
     cmd = "git rev-parse --abbrev-ref HEAD".split()
@@ -101,19 +87,8 @@ def get_base_branch():
 @status("Getting the list of files that have been added/changed",
         info=lambda x: n_files_str(len(x)))
 def changed_files(base_branch=None):
-    """Get the list of changed or added files from Mercurial or git."""
-    if os.path.isdir(os.path.join(SRCDIR, '.hg')):
-        if base_branch is not None:
-            sys.exit('need a git checkout to check PR status')
-        cmd = 'hg status --added --modified --no-status'
-        if mq_patches_applied():
-            cmd += ' --rev qparent'
-        st = subprocess.Popen(cmd.split(), stdout=subprocess.PIPE)
-        try:
-            filenames = [x.decode().rstrip() for x in st.stdout]
-        finally:
-            st.stdout.close()
-    elif os.path.exists(os.path.join(SRCDIR, '.git')):
+    """Get the list of changed or added files from git."""
+    if os.path.exists(os.path.join(SRCDIR, '.git')):
         # We just use an existence check here as:
         #  directory = normal git checkout/clone
         #  file = git worktree directory
@@ -138,7 +113,7 @@ def changed_files(base_branch=None):
         finally:
             st.stdout.close()
     else:
-        sys.exit('need a Mercurial or git checkout to get modified files')
+        sys.exit('need a git checkout to get modified files')
 
     filenames2 = []
     for filename in filenames: