minstall: Treat symlinks to directories as directories if follow_symlinks is enabled in do_copydir()

Fix the installation of a subdirectory that contains a symlink to a
directory, when follow_symlinks is enabled.

Currently, the following error is thrown in that case:

> IsADirectoryError: [Errno 21] Is a directory: '<path to symlink to directory>'

mesonbuild/minstall.py

@@ -507,13 +507,13 @@ class Installer:
             exclude_dirs = {os.path.normpath(x) for x in exclude_dirs}
         else:
             exclude_files = exclude_dirs = set()
-        for root, dirs, files in os.walk(src_dir):
+        for root, dirs, files in os.walk(src_dir, followlinks=bool(follow_symlinks)):
             assert os.path.isabs(root)
             for d in dirs[:]:
                 abs_src = os.path.join(root, d)
                 filepart = os.path.relpath(abs_src, start=src_dir)
                 abs_dst = os.path.join(dst_dir, filepart)
-                if os.path.islink(abs_src):
+                if not follow_symlinks and os.path.islink(abs_src):
                     files.append(d)
                     continue
                 # Remove these so they aren't visited by os.walk at all.

run_format_tests.py

@@ -72,6 +72,8 @@ def check_symlinks():
         if f.is_symlink():
             if 'boost symlinks/boost/lib' in str(f):
                 continue
+            if 'follow symlinks/bar/dir2/dir3' in str(f):
+                continue
             raise SystemExit(f'Test data dir contains symlink: {f}.')
 
 

test cases/common/268 install functions and follow symlinks/bar/dir2/dir3

@@ -0,0 +1 @@
+../dir1

test cases/common/268 install functions and follow symlinks/meson.build

@@ -40,3 +40,15 @@ install_subdir(
   strip_directory: true,
   follow_symlinks: true,
 )
+
+install_subdir(
+  'bar',
+  install_dir: get_option('datadir') / 'subdir',
+  follow_symlinks: false,
+)
+
+install_subdir(
+  'bar',
+  install_dir: get_option('datadir') / 'subdir_followed',
+  follow_symlinks: true,
+)

test cases/common/268 install functions and follow symlinks/test.json

@@ -7,8 +7,12 @@
     {"type": "link", "file": "usr/share/subdir/link1"},
     {"type": "link", "file": "usr/share/subdir/link2.h"},
     {"type": "file", "file": "usr/share/subdir/file1"},
+    {"type": "file", "file": "usr/share/subdir/bar/dir1/file1"},
+    {"type": "link", "file": "usr/share/subdir/bar/dir2/dir3"},
     {"type": "file", "file": "usr/share/subdir_followed/link1"},
     {"type": "file", "file": "usr/share/subdir_followed/link2.h"},
-    {"type": "file", "file": "usr/share/subdir_followed/file1"}
+    {"type": "file", "file": "usr/share/subdir_followed/file1"},
+    {"type": "file", "file": "usr/share/subdir_followed/bar/dir1/file1"},
+    {"type": "file", "file": "usr/share/subdir_followed/bar/dir2/dir3/file1"}
   ]
 }