ash: fix prompt expansion (Natanael Copa <natanael.copa@gmail.com>)

1 files changed, 17 insertions, 2 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 167232c33..a3bfe3977 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -2494,6 +2494,7 @@ pwdcmd(int argc, char **argv)
 #define DQSYNTAX   1    /* in double quotes */
 #define SQSYNTAX   2    /* in single quotes */
 #define ARISYNTAX  3    /* in arithmetic */
+#define PSSYNTAX   4    /* prompt */
 
 #if ENABLE_ASH_OPTIMIZE_FOR_SIZE
 #define USE_SIT_FUNCTION
@@ -9886,6 +9887,9 @@ readtoken1(int firstc, int syntax, char *eofmark, int striptabs)
         smallint dblquote;
         smallint oldstyle;
         smallint prevsyntax; /* syntax before arithmetic */
+#if ENABLE_ASH_EXPAND_PRMT
+        smallint pssyntax;   /* we are expanding a prompt string */
+#endif
         int varnest;         /* levels of variables expansion */
         int arinest;         /* levels of arithmetic expansion */
         int parenlevel;      /* levels of parens in arithmetic */
@@ -9907,9 +9911,14 @@ readtoken1(int firstc, int syntax, char *eofmark, int striptabs)
         startlinno = plinno;
         bqlist = NULL;
         quotef = 0;
-        dblquote = (syntax == DQSYNTAX);
         oldstyle = 0;
         prevsyntax = 0;
+#if ENABLE_ASH_EXPAND_PRMT
+        pssyntax = (syntax == PSSYNTAX);
+        if (pssyntax)
+                syntax = DQSYNTAX;
+#endif
+        dblquote = (syntax == DQSYNTAX);
         varnest = 0;
         arinest = 0;
         parenlevel = 0;
@@ -9948,6 +9957,12 @@ readtoken1(int firstc, int syntax, char *eofmark, int striptabs)
                                         if (doprompt)
                                                 setprompt(2);
                                 } else {
+#if ENABLE_ASH_EXPAND_PRMT
+                                        if (c == '$' && pssyntax) {
+                                                USTPUTC(CTLESC, out);
+                                                USTPUTC('\\', out);
+                                        }
+#endif
                                         if (dblquote &&
                                                 c != '\\' && c != '`' &&
                                                 c != '$' && (
@@ -10780,7 +10795,7 @@ expandstr(const char *ps)
 
         /* XXX Fix (char *) cast. */
         setinputstring((char *)ps);
-        readtoken1(pgetc(), DQSYNTAX, nullstr, 0);
+        readtoken1(pgetc(), PSSYNTAX, nullstr, 0);
         popfile();
 
         n.narg.type = NARG;