Merge branch 'ld/p4-current-branch-fix'

"git p4" used "name-rev HEAD" when it wants to learn what branch is
checked out; it should use "symbolic-ref HEAD".

* ld/p4-current-branch-fix:
  git-p4: don't use name-rev to get current branch
  git-p4: add read_pipe_text() internal function
  git-p4: add failing test for name-rev rather than symbolic-ref

Author: gitster

git-p4.py

@@ -160,17 +160,42 @@ def p4_write_pipe(c, stdin):
     real_cmd = p4_build_cmd(c)
     return write_pipe(real_cmd, stdin)
 
-def read_pipe(c, ignore_error=False):
+def read_pipe_full(c):
+    """ Read output from  command. Returns a tuple
+        of the return status, stdout text and stderr
+        text.
+    """
     if verbose:
         sys.stderr.write('Reading pipe: %s\n' % str(c))
 
     expand = isinstance(c,basestring)
     p = subprocess.Popen(c, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=expand)
     (out, err) = p.communicate()
-    if p.returncode != 0 and not ignore_error:
-        die('Command failed: %s\nError: %s' % (str(c), err))
+    return (p.returncode, out, err)
+
+def read_pipe(c, ignore_error=False):
+    """ Read output from  command. Returns the output text on
+        success. On failure, terminates execution, unless
+        ignore_error is True, when it returns an empty string.
+    """
+    (retcode, out, err) = read_pipe_full(c)
+    if retcode != 0:
+        if ignore_error:
+            out = ""
+        else:
+            die('Command failed: %s\nError: %s' % (str(c), err))
     return out
 
+def read_pipe_text(c):
+    """ Read output from a command with trailing whitespace stripped.
+        On error, returns None.
+    """
+    (retcode, out, err) = read_pipe_full(c)
+    if retcode != 0:
+        return None
+    else:
+        return out.rstrip()
+
 def p4_read_pipe(c, ignore_error=False):
     real_cmd = p4_build_cmd(c)
     return read_pipe(real_cmd, ignore_error)
@@ -577,12 +602,7 @@ def p4Where(depotPath):
     return clientPath
 
 def currentGitBranch():
-    retcode = system(["git", "symbolic-ref", "-q", "HEAD"], ignore_error=True)
-    if retcode != 0:
-        # on a detached head
-        return None
-    else:
-        return read_pipe(["git", "name-rev", "HEAD"]).split(" ")[1].strip()
+    return read_pipe_text(["git", "symbolic-ref", "--short", "-q", "HEAD"])
 
 def isValidGitDir(path):
     return git_dir(path) != None

t/t9807-git-p4-submit.sh

@@ -139,6 +139,22 @@ test_expect_success 'submit with master branch name from argv' '
 	)
 '
 
+test_expect_success 'allow submit from branch with same revision but different name' '
+	test_when_finished cleanup_git &&
+	git p4 clone --dest="$git" //depot &&
+	(
+		cd "$git" &&
+		test_commit "file8" &&
+		git checkout -b branch1 &&
+		git checkout -b branch2 &&
+		git config git-p4.skipSubmitEdit true &&
+		git config git-p4.allowSubmit "branch1" &&
+		test_must_fail git p4 submit &&
+		git checkout branch1 &&
+		git p4 submit
+	)
+'
+
 #
 # Basic submit tests, the five handled cases
 #