shell/ash: replace updatepwd()

1 files changed, 89 insertions, 0 deletions

diff --git a/shell/ash_mingw.c b/shell/ash_mingw.c
index c36973164..42a9e41a7 100644
--- a/shell/ash_mingw.c
+++ b/shell/ash_mingw.c
@@ -1041,3 +1041,92 @@ static int set_exitstatus(int val, const char **argv,int *out)
         return -1;
 }
 
+static const char *
+updatepwd(const char *dir)
+{
+        char *new;
+        char *p;
+        char *cdcomppath;
+        const char *lim;
+        /*
+         * There are four cases
+         *  absdrive +  abspath: c:/path
+         *  absdrive + !abspath: c:path
+         * !absdrive +  abspath: /path
+         * !absdrive + !abspath: path
+         *
+         * Damn DOS!
+         * c:path behaviour is "undefined"
+         * To properly handle this case, I have to keep track of cwd
+         * of every drive, which is too painful to do.
+         * So when c:path is given, I assume it's c:${curdir}path
+         * with ${curdir} comes from the current drive
+         */
+        int absdrive = *dir && dir[1] == ':';
+        int abspath = absdrive ? dir[2] == '/' : *dir == '/';
+        char *drive;
+
+        cdcomppath = ststrdup(dir);
+        STARTSTACKSTR(new);
+        if (!absdrive && curdir == nullstr)
+                return 0;
+        if (!abspath) {
+                if (curdir == nullstr)
+                        return 0;
+                new = stack_putstr(curdir, new);
+        }
+        new = makestrspace(strlen(dir) + 2, new);
+
+        drive = stackblock();
+        if (absdrive) {
+                *drive = *dir;
+                cdcomppath += 2;
+                dir += 2;
+        } else {
+                *drive = *curdir;
+        }
+        drive[1] = ':'; /* in case of absolute drive+path */
+
+        if (abspath)
+                new = drive + 2;
+        lim = drive + 3;
+        if (!abspath) {
+                if (new[-1] != '/')
+                        USTPUTC('/', new);
+                if (new > lim && *lim == '/')
+                        lim++;
+        } else {
+                USTPUTC('/', new);
+                cdcomppath ++;
+                if (dir[1] == '/' && dir[2] != '/') {
+                        USTPUTC('/', new);
+                        cdcomppath++;
+                        lim++;
+                }
+        }
+        p = strtok(cdcomppath, "/");
+        while (p) {
+                switch (*p) {
+                case '.':
+                        if (p[1] == '.' && p[2] == '\0') {
+                                while (new > lim) {
+                                        STUNPUTC(new);
+                                        if (new[-1] == '/')
+                                                break;
+                                }
+                                break;
+                        }
+                        if (p[1] == '\0')
+                                break;
+                        /* fall through */
+                default:
+                        new = stack_putstr(p, new);
+                        USTPUTC('/', new);
+                }
+                p = strtok(0, "/");
+        }
+        if (new > lim)
+                STUNPUTC(new);
+        *new = 0;
+        return stackblock();
+}