wrap: Add support for applying a list of patch files

Co-authored-by: Xavier Claessens <xavier.claessens@collabora.com>

docs/markdown/Wrap-dependency-system-manual.md

@@ -84,6 +84,8 @@ previously reserved to `wrap-file`:
 - `patch_directory` - *Since 0.55.0* Overlay directory, alternative to `patch_filename` in the case
   files are local instead of a downloaded archive. The directory must be placed in
   `subprojects/packagefiles`.
+- `diff_files` - *Since 0.61.0* Comma-separated list of local diff files (see
+  [Diff files](#diff-files) below).
 
 ### Specific to wrap-file
 - `source_url` - download url to retrieve the wrap-file source archive
@@ -147,6 +149,37 @@ wrap-file mode. When using wrap-git, the repository must contain all
 Meson build definitions. Since *0.55.0* Meson build patches are
 supported for any wrap modes, including wrap-git.
 
+## Diff files
+
+*Since: 0.61.0*
+
+You can also provide local patch files in `diff` format. For historic reasons,
+they are referred to as "diff files", since the "patch" name is already used for
+Meson build patches.
+
+The diff files are described by the `diff_files` property (a comma-separated
+list), and must be available locally in the `subprojects/packagefiles`
+directory.
+
+Meson will apply the diff files after extracting or cloning the project, and
+after applying the build patches (`patch_*`). For this feature, `patch` or `git`
+command-line tool must be available.
+
+The diff files will be applied with `-p1`, i.e. treating the first path
+component as prefix to be stripped. This is the default for diffs produced by
+Git.
+
+```ini
+[wrap-file]
+directory = libfoobar-1.0
+
+source_url = https://example.com/foobar-1.0.tar.gz
+source_filename = foobar-1.0.tar.gz
+source_hash = 5ebeea0dfb75d090ea0e7ff84799b2a7a1550db3fe61eb5f6f61c2e971e57663
+
+diff_files = libfoobar-0001.patch, libfoobar-0002.patch
+```
+
 ## `provide` section
 
 *Since *0.55.0*

mesonbuild/wrap/wrap.py

@@ -31,7 +31,7 @@
 from pathlib import Path
 from . import WrapMode
 from .. import coredata
-from ..mesonlib import quiet_git, GIT, ProgressBar, MesonException
+from ..mesonlib import quiet_git, GIT, ProgressBar, MesonException, Popen_safe
 from ..interpreterbase import FeatureNew
 from .. import mesonlib
 
@@ -52,6 +52,8 @@
 
 ALL_TYPES = ['file', 'git', 'hg', 'svn']
 
+PATCH = shutil.which('patch')
+
 def whitelist_wrapdb(urlstr: str) -> urllib.parse.ParseResult:
     """ raises WrapException if not whitelisted subdomain """
     url = urllib.parse.urlparse(urlstr)
@@ -98,6 +100,7 @@ def __init__(self, fname: str, subproject: str = ''):
         self.values = {} # type: T.Dict[str, str]
         self.provided_deps = {} # type: T.Dict[str, T.Optional[str]]
         self.provided_programs = [] # type: T.List[str]
+        self.diff_files = [] # type: T.List[str]
         self.basename = os.path.basename(fname)
         self.has_wrap = self.basename.endswith('.wrap')
         self.name = self.basename[:-5] if self.has_wrap else self.basename
@@ -159,6 +162,10 @@ def parse_wrap_section(self, config: configparser.ConfigParser) -> None:
             raise WrapException(f'{self.wrap_section!r} is not a valid first section in {self.basename}')
         self.type = self.wrap_section[5:]
         self.values = dict(config[self.wrap_section])
+        if 'diff_files' in self.values:
+            FeatureNew('Wrap files with diff_files', '0.61.0').use(self.subproject)
+            diff_files = [s.strip() for s in self.values['diff_files'].split(',')]
+            self.diff_files += diff_files
 
     def parse_provide_section(self, config: configparser.ConfigParser) -> None:
         if config.has_section('provide'):
@@ -343,6 +350,7 @@ def resolve(self, packagename: str, method: str) -> str:
                 else:
                     raise WrapException(f'Unknown wrap type {self.wrap.type!r}')
             self.apply_patch()
+            self.apply_diff_files()
 
         # A meson.build or CMakeLists.txt file is required in the directory
         if method == 'meson' and not os.path.exists(meson_file):
@@ -587,6 +595,29 @@ def apply_patch(self) -> None:
                 raise WrapException(f'patch directory does not exist: {patch_dir}')
             self.copy_tree(src_dir, self.dirname)
 
+    def apply_diff_files(self) -> None:
+        for filename in self.wrap.diff_files:
+            mlog.log(f'Applying diff file "{filename}"')
+            path = Path(self.wrap.filesdir) / filename
+            if not path.exists():
+                raise WrapException(f'Diff file "{path}" does not exist')
+            if False and PATCH:
+                cmd = [PATCH, '-f', '-p1', '-i', str(path)]
+            elif GIT:
+                # If the `patch` command is not available, fall back to `git
+                # apply`. The `--work-tree` is necessary in case we're inside a
+                # Git repository: by default, Git will try to apply the patch to
+                # the repository root.
+                cmd = [GIT, '--work-tree', '.', 'apply', '-p1', str(path)]
+            else:
+                raise WrapException(
+                    'Missing "patch" or "git" commands to apply diff files')
+
+            p, out, _ = Popen_safe(cmd, cwd=self.dirname, stderr=subprocess.STDOUT)
+            if p.returncode != 0:
+                mlog.log(out.strip())
+                raise WrapException(f'Failed to apply diff file "{filename}"')
+
     def copy_tree(self, root_src_dir: str, root_dst_dir: str) -> None:
         """
         Copy directory tree. Overwrites also read only files.

test cases/common/153 wrap file should not failed/meson.build

@@ -14,3 +14,8 @@ executable('grabprog2', files('src/subprojects/foo/prog2.c'))
 subdir('src')
 
 subproject('patchdir')
+
+if find_program('patch', required : false).found() or find_program('git', required : false).found()
+  exe = subproject('patchfile').get_variable('foo_exe')
+  test('test_foo', exe)
+endif

test cases/common/153 wrap file should not failed/subprojects/packagefiles/patchfile/0001-Change-foo-to-executable.patch

@@ -0,0 +1,33 @@
+From b79f6cc4a096f6c2888f73b947b652491885896a Mon Sep 17 00:00:00 2001
+From: Xavier Claessens <xavier.claessens@collabora.com>
+Date: Fri, 30 Nov 2018 14:13:47 -0500
+Subject: [PATCH] Change foo to executable
+
+---
+ foo.c       | 4 ++++
+ meson.build | 2 +-
+ 2 files changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/foo.c b/foo.c
+index 54f9119..468f033 100644
+--- a/foo.c
++++ b/foo.c
+@@ -1,3 +1,7 @@
+ int dummy_func(void) {
+     return 44;
+ }
++
++int main(void) {
++    return dummy_func() == 44 ? 0 : 1;
++}
+diff --git a/meson.build b/meson.build
+index 318e81d..4a281d9 100644
+--- a/meson.build
++++ b/meson.build
+@@ -1,2 +1,2 @@
+ project('static lib patchdir', 'c')
+-libfoo = static_library('foo', 'foo.c')
++foo_exe = executable('foo', 'foo.c')
+-- 
+2.17.1
+

test cases/common/153 wrap file should not failed/subprojects/packagefiles/patchfile/0001-Change-return-value-to-43.patch

@@ -0,0 +1,21 @@
+From 7001dcc738e5ae7dfa8af20ed582b9a985804f72 Mon Sep 17 00:00:00 2001
+From: Xavier Claessens <xavier.claessens@collabora.com>
+Date: Fri, 30 Nov 2018 10:15:33 -0500
+Subject: [PATCH 1/2] Change return value to 43
+
+---
+ foo.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/foo.c b/foo.c
+index 019f2ba..e4577b8 100644
+--- a/foo.c
++++ b/foo.c
+@@ -1,3 +1,3 @@
+ int dummy_func(void) {
+-    return 42;
++    return 43;
+ }
+-- 
+2.17.1
+

test cases/common/153 wrap file should not failed/subprojects/packagefiles/patchfile/0002-Change-return-value-to-44.patch

@@ -0,0 +1,21 @@
+From c2da2e490b09f2e251c7f4ef7c1240acee215fec Mon Sep 17 00:00:00 2001
+From: Xavier Claessens <xavier.claessens@collabora.com>
+Date: Fri, 30 Nov 2018 10:15:47 -0500
+Subject: [PATCH 2/2] Change return value to 44
+
+---
+ foo.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/foo.c b/foo.c
+index e4577b8..54f9119 100644
+--- a/foo.c
++++ b/foo.c
+@@ -1,3 +1,3 @@
+ int dummy_func(void) {
+-    return 43;
++    return 44;
+ }
+-- 
+2.17.1
+

test cases/common/153 wrap file should not failed/subprojects/patchfile.wrap

@@ -0,0 +1,14 @@
+[wrap-file]
+directory = foo-1.0-patchfile
+
+source_url = http://something.invalid
+source_filename = foo-1.0.tar.xz
+source_hash = 9ed8f67d75e43d3be161efb6eddf30dd01995a958ca83951ea64234bac8908c1
+lead_directory_missing = true
+
+patch_directory = foo-1.0
+
+diff_files =
+  patchfile/0001-Change-return-value-to-43.patch,
+  patchfile/0002-Change-return-value-to-44.patch,
+  patchfile/0001-Change-foo-to-executable.patch