[04/19] compat/win32: fix const-correctness with string constants

Commit Message

Patrick Steinhardt May 29, 2024, 12:44 p.m. UTC

Adjust various places in our Win32 compatibility layer where we are not
assigning string constants to `const char *` variables.

Signed-off-by: Patrick Steinhardt <[e-mail]>
---
 compat/basename.c | 15 +++++++++++++--
 compat/mingw.c    | 25 +++++++++++++------------
 compat/winansi.c  |  2 +-
 3 files changed, 27 insertions(+), 15 deletions(-)

Patch

diff --git a/compat/basename.c b/compat/basename.c
index 96bd9533b4..c3c9d65fac 100644
--- a/compat/basename.c
+++ b/compat/basename.c
@@ -1,6 +1,13 @@ 
 #include "../git-compat-util.h"
 #include "../strbuf.h"
 
+/*
+ * Both basename(3P) and dirname(3P) are mis-specified because they return a
+ * non-constant pointer even though it is specified that they may return a
+ * pointer to internal memory. This variable here is a result of that.
+ */
+static char current_directory[] = ".";
+
 /* Adapted from libiberty's basename.c.  */
 char *gitbasename (char *path)
 {
@@ -10,7 +17,7 @@  char *gitbasename (char *path)
 		skip_dos_drive_prefix(&path);
 
 	if (!path || !*path)
-		return ".";
+		return current_directory;
 
 	for (base = path; *path; path++) {
 		if (!is_dir_sep(*path))
@@ -33,8 +40,12 @@  char *gitdirname(char *path)
 	char *p = path, *slash = NULL, c;
 	int dos_drive_prefix;
 
+	/*
+	 * Same here, dirname(3P) is broken because it returns a non-constant
+	 * pointer that may point to internal memory.
+	 */
 	if (!p)
-		return ".";
+		return current_directory;
 
 	if ((dos_drive_prefix = skip_dos_drive_prefix(&p)) && !*p)
 		goto dot;
diff --git a/compat/mingw.c b/compat/mingw.c
index 6b06ea540f..60f0986f76 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2257,6 +2257,7 @@  struct passwd *getpwuid(int uid)
 {
 	static unsigned initialized;
 	static char user_name[100];
+	static char unknown[] = "unknown";
 	static struct passwd *p;
 	wchar_t buf[100];
 	DWORD len;
@@ -2279,7 +2280,7 @@  struct passwd *getpwuid(int uid)
 	p->pw_name = user_name;
 	p->pw_gecos = get_extended_user_info(NameDisplay);
 	if (!p->pw_gecos)
-		p->pw_gecos = "unknown";
+		p->pw_gecos = unknown;
 	p->pw_dir = NULL;
 
 	initialized = 1;
@@ -2800,16 +2801,16 @@  int is_path_owned_by_current_sid(const char *path, struct strbuf *report)
 			strbuf_addf(report, "'%s' is on a file system that does "
 				    "not record ownership\n", path);
 		} else if (report) {
-			LPSTR str1, str2, str3, str4, to_free1 = NULL,
-			    to_free3 = NULL, to_local_free2 = NULL,
-			    to_local_free4 = NULL;
+			PCSTR str1, str2, str3, str4;
+			LPSTR to_free1 = NULL, to_free3 = NULL,
+			    to_local_free2 = NULL, to_local_free4 = NULL;
 
-			if (user_sid_to_user_name(sid, &str1))
-				to_free1 = str1;
+			if (user_sid_to_user_name(sid, &to_free1))
+				str1 = to_free1;
 			else
 				str1 = "(inconvertible)";
-			if (ConvertSidToStringSidA(sid, &str2))
-				to_local_free2 = str2;
+			if (ConvertSidToStringSidA(sid, &to_local_free2))
+				str2 = to_local_free2;
 			else
 				str2 = "(inconvertible)";
 
@@ -2822,13 +2823,13 @@  int is_path_owned_by_current_sid(const char *path, struct strbuf *report)
 				str4 = "(invalid)";
 			} else {
 				if (user_sid_to_user_name(current_user_sid,
-							  &str3))
-					to_free3 = str3;
+							  &to_free3))
+					str3 = to_free3;
 				else
 					str3 = "(inconvertible)";
 				if (ConvertSidToStringSidA(current_user_sid,
-							   &str4))
-					to_local_free4 = str4;
+							   &to_local_free4))
+					str4 = to_local_free4;
 				else
 					str4 = "(inconvertible)";
 			}
diff --git a/compat/winansi.c b/compat/winansi.c
index f83610f684..575813bde8 100644
--- a/compat/winansi.c
+++ b/compat/winansi.c
@@ -139,7 +139,7 @@  static void write_console(unsigned char *str, size_t len)
 	/* convert utf-8 to utf-16 */
 	int wlen = xutftowcsn(wbuf, (char*) str, ARRAY_SIZE(wbuf), len);
 	if (wlen < 0) {
-		wchar_t *err = L"[invalid]";
+		const wchar_t *err = L"[invalid]";
 		WriteConsoleW(console, err, wcslen(err), &dummy, NULL);
 		return;
 	}