13 files changed, 127 insertions, 44 deletions

diff --git a/docs/markdown/External-commands.md b/docs/markdown/External-commands.md
index 4c8c8e4..cafd280 100644
--- a/docs/markdown/External-commands.md
+++ b/docs/markdown/External-commands.md
@@ -16,7 +16,14 @@ output = r.stdout().strip()
 errortxt = r.stderr().strip()
 ```
 
-Additionally, since 0.50.0, you can pass the command [`environment`](Reference-manual.html#environment-object) object:
+Since 0.52.0, you can pass the command environment as a dictionary:
+
+```meson
+run_command('command', 'arg1', 'arg2', env: {'FOO': 'bar'})
+```
+
+Since 0.50.0, you can also pass the command
+[`environment`](Reference-manual.html#environment-object) object:
 
 ```meson
 env = environment()
diff --git a/docs/markdown/Reference-manual.md b/docs/markdown/Reference-manual.md
index f296e43..6009d30 100644
--- a/docs/markdown/Reference-manual.md
+++ b/docs/markdown/Reference-manual.md
@@ -104,7 +104,10 @@ Add a custom test setup that can be used to run the tests with a
 custom setup, for example under Valgrind. The keyword arguments are
 the following:
 
-- `env` an [environment object](#environment-object) to use a custom environment
+- `env` environment variables to set, such as `['NAME1=value1',
+  'NAME2=value2']`, or an [`environment()`
+  object](#environment-object) which allows more sophisticated
+  environment juggling. *Since 0.52.0* a dictionary is also accepted.
 - `exe_wrapper` a list containing the wrapper command or script followed by the arguments to it
 - `gdb` if `true`, the tests are also run under `gdb`
 - `timeout_multiplier` a number to multiply the test timeout with
@@ -491,12 +494,16 @@ Print the argument string and halts the build process.
 ### environment()
 
 ``` meson
-    environment_object environment()
+    environment_object environment(...)
 ```
 
 Returns an empty [environment variable
 object](#environment-object). Added in 0.35.0.
 
+Since *0.52.0* takes an optional dictionary as first argument. If
+provided, each key/value pair is added into the `environment_object`
+as if `set()` method was called for each of them.
+
 ### executable()
 
 ``` meson
@@ -1256,7 +1263,10 @@ This function supports the following keyword arguments:
    be checked, and the configuration will fail if it is non-zero. The default is
    `false`.
    Since 0.47.0
- - `env` an [environment object](#environment-object) to use a custom environment
+ - `env` environment variables to set, such as `['NAME1=value1',
+   'NAME2=value2']`, or an [`environment()`
+   object](#environment-object) which allows more sophisticated
+   environment juggling. *Since 0.52.0* a dictionary is also accepted.
    Since 0.50.0
 
 See also [External commands](External-commands.md).
@@ -1489,7 +1499,7 @@ Keyword arguments are the following:
 - `env` environment variables to set, such as `['NAME1=value1',
   'NAME2=value2']`, or an [`environment()`
   object](#environment-object) which allows more sophisticated
-  environment juggling
+  environment juggling. *Since 0.52.0* a dictionary is also accepted.
 
 - `is_parallel` when false, specifies that no other test must be
   running at the same time as this test
diff --git a/docs/markdown/Release-notes-for-0.52.0.md b/docs/markdown/Release-notes-for-0.52.0.md
index de317df..f5bbcc3 100644
--- a/docs/markdown/Release-notes-for-0.52.0.md
+++ b/docs/markdown/Release-notes-for-0.52.0.md
@@ -3,13 +3,4 @@ title: Release 0.52.0
 short-description: Release notes for 0.52.0
 ...
 
-# New features
-
-## Allow checking if a variable is a disabler
-
-Added the function `is_disabler(var)`. Returns true if a variable is a disabler
-and false otherwise.
-
-## Add blocks dependency
-
-Add `dependency('blocks')` to use the Clang blocks extension.
+# Notable changes in this version
diff --git a/docs/markdown/Videos.md b/docs/markdown/Videos.md
index 65fccfe..f2e37a7 100644
--- a/docs/markdown/Videos.md
+++ b/docs/markdown/Videos.md
@@ -4,6 +4,9 @@ short-description: Videos about Meson
 
 # Videos
 
+ - [Behind the Scenes of a C++ Build
+   System](https://www.youtube.com/watch?v=34KzT2yvQuM) CppCon 2019
+
  - [Compiling Multi-Million Line C++ Code Bases Effortlessly with the
    Meson Build system](https://www.youtube.com/watch?v=SCZLnopmYBM),
    CppCon 2018
diff --git a/docs/markdown/Wrap-dependency-system-manual.md b/docs/markdown/Wrap-dependency-system-manual.md
index 619492a..22ba589 100644
--- a/docs/markdown/Wrap-dependency-system-manual.md
+++ b/docs/markdown/Wrap-dependency-system-manual.md
@@ -143,6 +143,14 @@ automatically by adding the following *(since 0.48.0)*:
 clone-recursive = true
 ```
 
+Setting the clone depth is supported using the `depth` directive *(since 0.52.0)*.
+Note that git always allow shallowly cloning branches, but in order to clone commit ids
+shallowly, the server must support `uploadpack.allowReachableSHA1InWant=true`.
+
+```ini
+depth = 1
+```
+
 ## Using wrapped projects
 
 Wraps provide a convenient way of obtaining a project into your subproject directory. 
diff --git a/docs/markdown/snippets/blocks.md b/docs/markdown/snippets/blocks.md
new file mode 100644
index 0000000..917ee54
--- /dev/null
+++ b/docs/markdown/snippets/blocks.md
@@ -0,0 +1,3 @@
+## Add blocks dependency
+
+Add `dependency('blocks')` to use the Clang blocks extension.
diff --git a/docs/markdown/snippets/check-disabler.md b/docs/markdown/snippets/check-disabler.md
new file mode 100644
index 0000000..9670792
--- /dev/null
+++ b/docs/markdown/snippets/check-disabler.md
@@ -0,0 +1,5 @@
+## Allow checking if a variable is a disabler
+
+Added the function `is_disabler(var)`. Returns true if a variable is a disabler
+and false otherwise.
+
diff --git a/docs/markdown/snippets/depth.md b/docs/markdown/snippets/depth.md
new file mode 100644
index 0000000..bdb032c
--- /dev/null
+++ b/docs/markdown/snippets/depth.md
@@ -0,0 +1,7 @@
+## Add `depth` option to `wrap-git`
+
+To allow shallow cloning, an option `depth` has been added to `wrap-git`.
+This applies recursively to submodules when `clone-recursive` is set to `true`.
+
+Note that the git server may have to be configured to support shallow cloning
+not only for branches but also for tags.
diff --git a/docs/markdown/snippets/env_dict.md b/docs/markdown/snippets/env_dict.md
new file mode 100644
index 0000000..5949806
--- /dev/null
+++ b/docs/markdown/snippets/env_dict.md
@@ -0,0 +1,8 @@
+## Support taking environment values from a dictionary
+
+`environment()` now accepts a dictionary as first argument.  If
+provided, each key/value pair is added into the `environment_object`
+as if `set()` method was called for each of them.
+
+On the various functions that take an `env:` keyword argument, you may
+now give a dictionary.
diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index e0b17db..2a77eaa 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -222,13 +222,28 @@ class ConfigureFileHolder(InterpreterObject, ObjectHolder):
 
 
 class EnvironmentVariablesHolder(MutableInterpreterObject, ObjectHolder):
-    def __init__(self):
+    def __init__(self, initial_values=None):
         MutableInterpreterObject.__init__(self)
         ObjectHolder.__init__(self, build.EnvironmentVariables())
         self.methods.update({'set': self.set_method,
                              'append': self.append_method,
                              'prepend': self.prepend_method,
                              })
+        if isinstance(initial_values, dict):
+            for k, v in initial_values.items():
+                self.set_method([k, v], {})
+        elif isinstance(initial_values, list):
+            for e in initial_values:
+                if '=' not in e:
+                    raise InterpreterException('Env var definition must be of type key=val.')
+                (k, val) = e.split('=', 1)
+                k = k.strip()
+                val = val.strip()
+                if ' ' in k:
+                    raise InterpreterException('Env var key must not have spaces in it.')
+                self.set_method([k, val], {})
+        elif initial_values:
+            raise AssertionError('Unsupported EnvironmentVariablesHolder initial_values')
 
     def __repr__(self):
         repr_str = "<{0}: {1}>"
@@ -267,7 +282,7 @@ class EnvironmentVariablesHolder(MutableInterpreterObject, ObjectHolder):
 
 
 class ConfigurationDataHolder(MutableInterpreterObject, ObjectHolder):
-    def __init__(self, pv):
+    def __init__(self, pv, initial_values=None):
         MutableInterpreterObject.__init__(self)
         self.used = False # These objects become immutable after use in configure_file.
         ObjectHolder.__init__(self, build.ConfigurationData(), pv)
@@ -279,6 +294,11 @@ class ConfigurationDataHolder(MutableInterpreterObject, ObjectHolder):
                              'get_unquoted': self.get_unquoted_method,
                              'merge_from': self.merge_from_method,
                              })
+        if isinstance(initial_values, dict):
+            for k, v in initial_values.items():
+                self.set_method([k, v], {})
+        elif initial_values:
+            raise AssertionError('Unsupported ConfigurationDataHolder initial_values')
 
     def is_used(self):
         return self.used
@@ -2610,15 +2630,13 @@ external dependencies (including libraries) must go to "dependencies".''')
         if len(args) > 1:
             raise InterpreterException('configuration_data takes only one optional positional arguments')
         elif len(args) == 1:
+            FeatureNew('configuration_data dictionary', '0.49.0').use(self.subproject)
             initial_values = args[0]
             if not isinstance(initial_values, dict):
                 raise InterpreterException('configuration_data first argument must be a dictionary')
         else:
             initial_values = {}
-        cdata = ConfigurationDataHolder(self.subproject)
-        for k, v in initial_values.items():
-            cdata.set_method([k, v], {})
-        return cdata
+        return ConfigurationDataHolder(self.subproject, initial_values)
 
     def set_backend(self):
         # The backend is already set when parsing subprojects
@@ -3357,19 +3375,14 @@ This will become a hard error in the future.''' % kwargs['input'], location=self
         envlist = kwargs.get('env', EnvironmentVariablesHolder())
         if isinstance(envlist, EnvironmentVariablesHolder):
             env = envlist.held_object
+        elif isinstance(envlist, dict):
+            FeatureNew('environment dictionary', '0.52.0').use(self.subproject)
+            env = EnvironmentVariablesHolder(envlist)
+            env = env.held_object
         else:
             envlist = listify(envlist)
             # Convert from array to environment object
-            env = EnvironmentVariablesHolder()
-            for e in envlist:
-                if '=' not in e:
-                    raise InterpreterException('Env var definition must be of type key=val.')
-                (k, val) = e.split('=', 1)
-                k = k.strip()
-                val = val.strip()
-                if ' ' in k:
-                    raise InterpreterException('Env var key must not have spaces in it.')
-                env.set_method([k, val], {})
+            env = EnvironmentVariablesHolder(envlist)
             env = env.held_object
         return env
 
@@ -3668,10 +3681,8 @@ This will become a hard error in the future.''' % kwargs['input'], location=self
         if 'configuration' in kwargs:
             conf = kwargs['configuration']
             if isinstance(conf, dict):
-                cdata = ConfigurationDataHolder(self.subproject)
-                for k, v in conf.items():
-                    cdata.set_method([k, v], {})
-                conf = cdata
+                FeatureNew('configure_file.configuration dictionary', '0.49.0').use(self.subproject)
+                conf = ConfigurationDataHolder(self.subproject, conf)
             elif not isinstance(conf, ConfigurationDataHolder):
                 raise InterpreterException('Argument "configuration" is not of type configuration_data')
             mlog.log('Configuring', mlog.bold(output), 'using configuration')
@@ -3935,9 +3946,18 @@ different subdirectory.
             argsdict[lang] = argsdict.get(lang, []) + args
 
     @noKwargs
-    @noPosargs
+    @noArgsFlattening
     def func_environment(self, node, args, kwargs):
-        return EnvironmentVariablesHolder()
+        if len(args) > 1:
+            raise InterpreterException('environment takes only one optional positional arguments')
+        elif len(args) == 1:
+            FeatureNew('environment positional arguments', '0.52.0').use(self.subproject)
+            initial_values = args[0]
+            if not isinstance(initial_values, dict) and not isinstance(initial_values, list):
+                raise InterpreterException('environment first argument must be a dictionary or a list')
+        else:
+            initial_values = {}
+        return EnvironmentVariablesHolder(initial_values)
 
     @stringArgs
     @noKwargs
diff --git a/mesonbuild/wrap/wrap.py b/mesonbuild/wrap/wrap.py
index 4b2a323..89bc307 100644
--- a/mesonbuild/wrap/wrap.py
+++ b/mesonbuild/wrap/wrap.py
@@ -226,16 +226,21 @@ class Resolver:
             self.apply_patch()
 
     def get_git(self):
+        # git doesn't support directly cloning shallowly for commits,
+        # so we follow https://stackoverflow.com/a/43136160
+        subprocess.check_call(['git', 'init', self.directory], cwd=self.subdir_root)
+        subprocess.check_call(['git', 'remote', 'add', 'origin', self.wrap.get('url')],
+                              cwd=self.dirname)
+        git_options = []
         revno = self.wrap.get('revision')
-        subprocess.check_call(['git', 'clone', self.wrap.get('url'),
-                               self.directory], cwd=self.subdir_root)
-        if revno.lower() != 'head':
-            if subprocess.call(['git', 'checkout', revno], cwd=self.dirname) != 0:
-                subprocess.check_call(['git', 'fetch', self.wrap.get('url'), revno], cwd=self.dirname)
-                subprocess.check_call(['git', 'checkout', revno], cwd=self.dirname)
+        if self.wrap.values.get('depth', '') != '':
+            git_options.extend(['--depth', self.wrap.values.get('depth')])
+        subprocess.check_call(['git', 'fetch'] + git_options + ['origin', revno],
+                              cwd=self.dirname)
+        subprocess.check_call(['git', 'checkout', revno], cwd=self.dirname)
         if self.wrap.values.get('clone-recursive', '').lower() == 'true':
             subprocess.check_call(['git', 'submodule', 'update',
-                                   '--init', '--checkout', '--recursive'],
+                                   '--init', '--checkout', '--recursive'] + git_options,
                                   cwd=self.dirname)
         push_url = self.wrap.values.get('push-url')
         if push_url:
diff --git a/test cases/unit/69 test env value/meson.build b/test cases/unit/69 test env value/meson.build
new file mode 100644
index 0000000..aa3dbc3
--- /dev/null
+++ b/test cases/unit/69 test env value/meson.build
@@ -0,0 +1,10 @@
+project('test env value')
+
+testpy = find_program('test.py')
+
+val = ['1', '2', '3']
+foreach v: val
+    test('check env', testpy, args: [v], env: {'TEST_VAR': v})
+endforeach
+test('check env', testpy, args: ['4'], env: environment({'TEST_VAR': '4'}))
+test('check env', testpy, args: ['5'], env: environment(['TEST_VAR=5']))
diff --git a/test cases/unit/69 test env value/test.py b/test cases/unit/69 test env value/test.py
new file mode 100755
index 0000000..0cc7645
--- /dev/null
+++ b/test cases/unit/69 test env value/test.py
@@ -0,0 +1,6 @@
+#!/usr/bin/env python3
+
+import os
+import sys
+
+assert(os.environ['TEST_VAR'] == sys.argv[1])