4 files changed, 93 insertions, 1 deletions

diff --git a/compat/linux/procinfo.c b/compat/linux/procinfo.c
new file mode 100644
index 0000000000..578fed4cd3
--- /dev/null
+++ b/compat/linux/procinfo.c
@@ -0,0 +1,55 @@
+#include "cache.h"
+
+#include "strbuf.h"
+#include "strvec.h"
+#include "trace2.h"
+
+static void get_ancestry_names(struct strvec *names)
+{
+	/*
+	 * NEEDSWORK: We could gather the entire pstree into an array to match
+	 * functionality with compat/win32/trace2_win32_process_info.c.
+	 * To do so, we may want to examine /proc/<pid>/stat. For now, just
+	 * gather the immediate parent name which is readily accessible from
+	 * /proc/$(getppid())/comm.
+	 */
+	struct strbuf procfs_path = STRBUF_INIT;
+	struct strbuf name = STRBUF_INIT;
+
+	/* try to use procfs if it's present. */
+	strbuf_addf(&procfs_path, "/proc/%d/comm", getppid());
+	if (strbuf_read_file(&name, procfs_path.buf, 0)) {
+		strbuf_release(&procfs_path);
+		strbuf_trim_trailing_newline(&name);
+		strvec_push(names, strbuf_detach(&name, NULL));
+	}
+
+	return;
+	/* NEEDSWORK: add non-procfs-linux implementations here */
+}
+
+void trace2_collect_process_info(enum trace2_process_info_reason reason)
+{
+	if (!trace2_is_enabled())
+		return;
+
+	/* someday we may want to write something extra here, but not today */
+	if (reason == TRACE2_PROCESS_INFO_EXIT)
+		return;
+
+	if (reason == TRACE2_PROCESS_INFO_STARTUP) {
+		/*
+		 * NEEDSWORK: we could do the entire ptree in an array instead,
+		 * see compat/win32/trace2_win32_process_info.c.
+		 */
+		struct strvec names = STRVEC_INIT;
+
+		get_ancestry_names(&names);
+
+		if (names.nr)
+			trace2_cmd_ancestry(names.v);
+		strvec_clear(&names);
+	}
+
+	return;
+}
diff --git a/compat/mingw.c b/compat/mingw.c
index aa647b367b..9e0cd1e097 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -341,6 +341,27 @@ int mingw_rmdir(const char *pathname)
 {
 	int ret, tries = 0;
 	wchar_t wpathname[MAX_PATH];
+	struct stat st;
+
+	/*
+	 * Contrary to Linux' `rmdir()`, Windows' _wrmdir() and _rmdir()
+	 * (and `RemoveDirectoryW()`) will attempt to remove the target of a
+	 * symbolic link (if it points to a directory).
+	 *
+	 * This behavior breaks the assumption of e.g. `remove_path()` which
+	 * upon successful deletion of a file will attempt to remove its parent
+	 * directories recursively until failure (which usually happens when
+	 * the directory is not empty).
+	 *
+	 * Therefore, before calling `_wrmdir()`, we first check if the path is
+	 * a symbolic link. If it is, we exit and return the same error as
+	 * Linux' `rmdir()` would, i.e. `ENOTDIR`.
+	 */
+	if (!mingw_lstat(pathname, &st) && S_ISLNK(st.st_mode)) {
+		errno = ENOTDIR;
+		return -1;
+	}
+
 	if (xutftowcs_path(wpathname, pathname) < 0)
 		return -1;
 
diff --git a/compat/mmap.c b/compat/mmap.c
index 14d31010df..8d6c02d4bc 100644
--- a/compat/mmap.c
+++ b/compat/mmap.c
@@ -7,7 +7,12 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of
 	if (start != NULL || flags != MAP_PRIVATE || prot != PROT_READ)
 		die("Invalid usage of mmap when built with NO_MMAP");
 
-	start = xmalloc(length);
+	if (length == 0) {
+		errno = EINVAL;
+		return MAP_FAILED;
+	}
+
+	start = malloc(length);
 	if (start == NULL) {
 		errno = ENOMEM;
 		return MAP_FAILED;
diff --git a/compat/stub/procinfo.c b/compat/stub/procinfo.c
new file mode 100644
index 0000000000..12c0a23c9e
--- /dev/null
+++ b/compat/stub/procinfo.c
@@ -0,0 +1,11 @@
+#include "git-compat-util.h"
+
+#include "trace2.h"
+
+/*
+ * Stub. See sample implementations in compat/linux/procinfo.c and
+ * compat/win32/trace2_win32_process_info.c.
+ */
+void trace2_collect_process_info(enum trace2_process_info_reason reason)
+{
+}