ash: fix var_bash5.tests - ${VAR/pattern/repl} construct

function                                             old     new   delta
subevalvar                                          1198    1279     +81
rmescapes                                            308     330     +22
preglob                                                8      10      +2
parsefname                                           152     154      +2
expandarg                                            973     975      +2
argstr                                              1144    1146      +2
mklocal                                              290     288      -2
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 6/1 up/down: 111/-2)            Total: 109 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 72 insertions, 25 deletions

diff --git a/shell/ash.c b/shell/ash.c
index b73a79975..5381f34eb 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -5811,7 +5811,6 @@ ash_arith(const char *s)
 #define RMESCAPE_GLOB   0x2     /* Add backslashes for glob */
 #define RMESCAPE_GROW   0x8     /* Grow strings instead of stalloc */
 #define RMESCAPE_HEAP   0x10    /* Malloc strings instead of stalloc */
-#define RMESCAPE_SLASH  0x20    /* Stop globbing after slash */
 
 /* Add CTLESC when necessary. */
 #define QUOTES_ESC     (EXP_FULL | EXP_CASE | EXP_QPAT)
@@ -5992,8 +5991,12 @@ esclen(const char *start, const char *p)
 /*
  * Remove any CTLESC characters from a string.
  */
+#if !BASH_PATTERN_SUBST
+#define rmescapes(str, flag, slash_position) \
+        rmescapes(str, flag)
+#endif
 static char *
-rmescapes(char *str, int flag)
+rmescapes(char *str, int flag, int *slash_position)
 {
         static const char qchars[] ALIGN1 = {
                 IF_BASH_PATTERN_SUBST('/',) CTLESC, CTLQUOTEMARK, '\0' };
@@ -6002,9 +6005,8 @@ rmescapes(char *str, int flag)
         unsigned inquotes;
         unsigned protect_against_glob;
         unsigned globbing;
-        IF_BASH_PATTERN_SUBST(unsigned slash = flag & RMESCAPE_SLASH;)
 
-        p = strpbrk(str, qchars IF_BASH_PATTERN_SUBST(+ !slash));
+        p = strpbrk(str, qchars IF_BASH_PATTERN_SUBST(+ !slash_position));
         if (!p)
                 return str;
 
@@ -6084,10 +6086,11 @@ rmescapes(char *str, int flag)
                         goto copy;
                 }
 #if BASH_PATTERN_SUBST
-                else if (*p == '/' && slash) {
-                        /* stop handling globbing and mark location of slash */
-                        globbing = slash = 0;
-                        *p = CTLESC;
+                else if (slash_position && p == str + *slash_position) {
+                        /* stop handling globbing */
+                        globbing = 0;
+                        *slash_position = q - r;
+                        slash_position = NULL;
                 }
 #endif
                 protect_against_glob = globbing;
@@ -6111,7 +6114,7 @@ rmescapes(char *str, int flag)
 static char *
 preglob(const char *pattern, int flag)
 {
-        return rmescapes((char *)pattern, flag | RMESCAPE_GLOB);
+        return rmescapes((char *)pattern, flag | RMESCAPE_GLOB, NULL);
 }
 
 /*
@@ -6454,7 +6457,7 @@ expari(int flag)
         expdest = p;
 
         if (flag & QUOTES_ESC)
-                rmescapes(p + 1, 0);
+                rmescapes(p + 1, 0, NULL);
 
         len = cvtnum(ash_arith(p + 1));
 
@@ -6742,20 +6745,57 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
         char *rmesc, *rmescend;
         char *str;
         int amount, resetloc;
+        int argstr_flags;
         IF_BASH_PATTERN_SUBST(int workloc;)
-        IF_BASH_PATTERN_SUBST(char *repl = NULL;)
+        IF_BASH_PATTERN_SUBST(int slash_pos;)
+        IF_BASH_PATTERN_SUBST(char *repl;)
         int zero;
         char *(*scan)(char*, char*, char*, char*, int, int);
 
         //bb_error_msg("subevalvar(p:'%s',varname:'%s',strloc:%d,subtype:%d,startloc:%d,varflags:%x,quotes:%d)",
         //              p, varname, strloc, subtype, startloc, varflags, quotes);
 
-        argstr(p, EXP_TILDE | (subtype != VSASSIGN && subtype != VSQUESTION ?
-                        (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE) : 0)
-        );
+#if BASH_PATTERN_SUBST
+        repl = NULL;
+        if (subtype == VSREPLACE || subtype == VSREPLACEALL) {
+                /* Find '/' and replace with NUL */
+                repl = p;
+                for (;;) {
+                        /* Handle escaped slashes, e.g. "${v/\//_}" (they are CTLESC'ed by this point) */
+                        if (*repl == '\0') {
+                                repl = NULL;
+                                break;
+                        }
+                        if (*repl == '/') {
+                                *repl = '\0';
+                                break;
+                        }
+                        if ((unsigned char)*repl == CTLESC
+                         && repl[1]
+                        ) {
+                                repl++;
+                        }
+                        repl++;
+                }
+        }
+#endif
+        argstr_flags = EXP_TILDE;
+        if (subtype != VSASSIGN && subtype != VSQUESTION)
+                argstr_flags |= (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE);
+        argstr(p, argstr_flags);
+#if BASH_PATTERN_SUBST
+        slash_pos = -1;
+        if (repl) {
+                slash_pos = expdest - ((char *)stackblock() + strloc);
+                STPUTC('/', expdest);
+                argstr(repl + 1, argstr_flags);
+                *repl = '/';
+        }
+#endif
         STPUTC('\0', expdest);
         argbackq = saveargbackq;
         startp = (char *)stackblock() + startloc;
+        //bb_error_msg("str1:'%s'", (char *)stackblock() + strloc);
 
         switch (subtype) {
         case VSASSIGN:
@@ -6853,6 +6893,8 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
         resetloc = expdest - (char *)stackblock();
 
 #if BASH_PATTERN_SUBST
+        repl = NULL;
+
         /* We'll comeback here if we grow the stack while handling
          * a VSREPLACE or VSREPLACEALL, since our pointers into the
          * stack will need rebasing, and we'll need to remove our work
@@ -6867,8 +6909,10 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
 
         rmesc = startp;
         rmescend = (char *)stackblock() + strloc;
+        //bb_error_msg("str7:'%s'", rmescend);
         if (quotes) {
-                rmesc = rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW);
+//TODO: how to handle slash_pos here if string changes (shortens?)
+                rmesc = rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW, NULL);
                 if (rmesc != startp) {
                         rmescend = expdest;
                         startp = (char *)stackblock() + startloc;
@@ -6881,12 +6925,13 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
          * The result is a_\_z_c (not a\_\_z_c)!
          *
          * The search pattern and replace string treat backslashes differently!
-         * RMESCAPE_SLASH causes preglob to work differently on the pattern
+         * "&slash_pos" causes rmescapes() to work differently on the pattern
          * and string.  It's only used on the first call.
          */
-        preglob(str, IF_BASH_PATTERN_SUBST(
-                (subtype == VSREPLACE || subtype == VSREPLACEALL) && !repl ?
-                        RMESCAPE_SLASH : ) 0);
+        //bb_error_msg("str8:'%s' slash_pos:%d", str, slash_pos);
+        rmescapes(str, RMESCAPE_GLOB,
+                repl ? NULL : (slash_pos < 0 ? NULL : &slash_pos)
+        );
 
 #if BASH_PATTERN_SUBST
         workloc = expdest - (char *)stackblock();
@@ -6895,11 +6940,13 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
                 char *idx, *end;
 
                 if (!repl) {
-                        repl = strchr(str, CTLESC);
-                        if (repl)
+                        //bb_error_msg("str9:'%s' slash_pos:%d", str, slash_pos);
+                        if (slash_pos >= 0) {
+                                repl = str + slash_pos;
                                 *repl++ = '\0';
-                        else
+                        } else {
                                 repl = nullstr;
+                        }
                 }
                 //bb_error_msg("str:'%s' repl:'%s'", str, repl);
 
@@ -7419,7 +7466,7 @@ expandmeta(struct strlist *str /*, int flag*/)
                         INT_ON;
  nometa:
                         *exparg.lastp = str;
-                        rmescapes(str->text, 0);
+                        rmescapes(str->text, 0, NULL);
                         exparg.lastp = &str->next;
                         break;
                 default:        /* GLOB_NOSPACE */
@@ -7648,7 +7695,7 @@ expandmeta(struct strlist *str /*, int flag*/)
                          */
  nometa:
                         *exparg.lastp = str;
-                        rmescapes(str->text, 0);
+                        rmescapes(str->text, 0, NULL);
                         exparg.lastp = &str->next;
                 } else {
                         *exparg.lastp = NULL;
@@ -11328,7 +11375,7 @@ parsefname(void)
                 if (quoteflag == 0)
                         n->type = NXHERE;
                 TRACE(("Here document %d\n", n->type));
-                rmescapes(wordtext, 0);
+                rmescapes(wordtext, 0, NULL);
                 here->eofmark = wordtext;
                 here->next = NULL;
                 if (heredoclist == NULL)