Implement (*NOTEMPTY) and (?(VERSION= features.

src/pcre2.h.in

@@ -130,8 +130,8 @@ functions, so take care not to define synonyms by mistake. */
 
 #define PCRE2_NOTBOL              0x00000001u
 #define PCRE2_NOTEOL              0x00000002u
-#define PCRE2_NOTEMPTY            0x00000004u
+#define PCRE2_NOTEMPTY            0x00000004u  /* ) These two must be kept */
-#define PCRE2_NOTEMPTY_ATSTART    0x00000008u
+#define PCRE2_NOTEMPTY_ATSTART    0x00000008u  /* ) adjacent to each other. */
 #define PCRE2_PARTIAL_SOFT        0x00000010u
 #define PCRE2_PARTIAL_HARD        0x00000020u
 

src/pcre2_compile.c

@@ -566,7 +566,7 @@ enum { ERR0 = COMPILE_ERROR_BASE,
        ERR41, ERR42, ERR43, ERR44, ERR45, ERR46, ERR47, ERR48, ERR49, ERR50,
        ERR51, ERR52, ERR53, ERR54, ERR55, ERR56, ERR57, ERR58, ERR59, ERR60,
        ERR61, ERR62, ERR63, ERR64, ERR65, ERR66, ERR67, ERR68, ERR69, ERR70,
-       ERR71, ERR72, ERR73, ERR74, ERR75, ERR76, ERR77, ERR78 };
+       ERR71, ERR72, ERR73, ERR74, ERR75, ERR76, ERR77, ERR78, ERR79 };
 
 /* This is a table of start-of-pattern options such as (*UTF) and settings such
 as (*LIMIT_MATCH=nnnn) and (*CRLF). For completeness and backward
@@ -574,6 +574,7 @@ compatibility, (*UTFn) is supported in the relevant libraries, but (*UTF) is
 generic and always supported. */
 
 enum { PSO_OPT,     /* Value is an option bit */
+       PSO_FLG,     /* Value is a flag bit */
        PSO_NL,      /* Value is a newline type */
        PSO_BSR,     /* Value is a \R type */
        PSO_LIMM,    /* Read integer value for match limit */
@@ -592,6 +593,8 @@ static pso pso_list[] = {
   { (uint8_t *)STRING_UTFn_RIGHTPAR,                PSO_OPT, PCRE2_UTF },
   { (uint8_t *)STRING_UTF_RIGHTPAR,              4, PSO_OPT, PCRE2_UTF },
   { (uint8_t *)STRING_UCP_RIGHTPAR,              4, PSO_OPT, PCRE2_UCP },
+  { (uint8_t *)STRING_NOTEMPTY_RIGHTPAR,         9, PSO_FLG, PCRE2_NOTEMPTY_SET },
+  { (uint8_t *)STRING_NOTEMPTY_ATSTART_RIGHTPAR,17, PSO_FLG, PCRE2_NE_ATST_SET },  
   { (uint8_t *)STRING_NO_AUTO_POSSESS_RIGHTPAR, 16, PSO_OPT, PCRE2_NO_AUTO_POSSESS },
   { (uint8_t *)STRING_NO_START_OPT_RIGHTPAR,    13, PSO_OPT, PCRE2_NO_START_OPTIMIZE },
   { (uint8_t *)STRING_LIMIT_MATCH_EQ,           12, PSO_LIMM, 0 },
@@ -854,7 +857,8 @@ for (;;)
     case OP_CLOSE:
     case OP_COMMIT:
     case OP_CREF:
-    case OP_DEF:
+    case OP_FALSE:
+    case OP_TRUE:
     case OP_DNCREF:
     case OP_DNRREF:
     case OP_DOLL:
@@ -1118,7 +1122,8 @@ for (;;)
     case OP_DNCREF:
     case OP_RREF:
     case OP_DNRREF:
-    case OP_DEF:
+    case OP_FALSE:
+    case OP_TRUE:
     code += PRIV(OP_lengths)[*code];
     break;
 
@@ -4449,10 +4454,12 @@ for (;; ptr++)
       PCRE2_UCHAR *bralink = NULL;
       PCRE2_UCHAR *brazeroptr = NULL;
 
-      /* Repeating a DEFINE group is pointless, but Perl allows the syntax, so
+      /* Repeating a DEFINE group (or any group where the condition is always
-      we just ignore the repeat. */
+      FALSE and there is only one branch) is pointless, but Perl allows the
+      syntax, so we just ignore the repeat. */
 
-      if (*previous == OP_COND && previous[LINK_SIZE+1] == OP_DEF)
+      if (*previous == OP_COND && previous[LINK_SIZE+1] == OP_FALSE &&
+          previous[GET(previous, 1)] != OP_ALT) 
         goto END_REPEAT;
 
       /* There is no sense in actually repeating assertions. The only potential
@@ -5160,9 +5167,65 @@ for (;; ptr++)
         name = NULL;      /* Always set to avoid warning */
         recno = 0;        /* Always set to avoid warning */
         
-        /* Check for a test for recursion in a named group. */
+        /* Point at character after (?( */
         
         ptr++;
+
+        /* Check for (?(VERSION[>]=n.m), which is a facility whereby indirect
+        users of PCRE2 via an application can discover which release of PCRE2 
+        is being used. */
+         
+        if (PRIV(strncmp_c8)(ptr, STRING_VERSION, 7) == 0 && 
+            ptr[7] != CHAR_RIGHT_PARENTHESIS)
+          {
+          BOOL ge = FALSE; 
+          int major = 0;
+          int minor = 0;
+             
+          ptr += 7;
+          if (*ptr == CHAR_GREATER_THAN_SIGN)
+            {
+            ge = TRUE;
+            ptr++;
+            }   
+            
+          /* NOTE: cannot write IS_DIGIT(*(++ptr)) here because IS_DIGIT
+          references its argument twice. */
+            
+          if (*ptr != CHAR_EQUALS_SIGN || (ptr++, !IS_DIGIT(*ptr)))
+            {    
+            *errorcodeptr = ERR79;
+            goto FAILED; 
+            } 
+
+          while (IS_DIGIT(*ptr)) major = major * 10 + *ptr++ - '0';
+          if (*ptr == CHAR_DOT)
+            {
+            ptr++; 
+            while (IS_DIGIT(*ptr)) minor = minor * 10 + *ptr++ - '0'; 
+            }     
+
+          if (*ptr != CHAR_RIGHT_PARENTHESIS)
+            {
+            *errorcodeptr = ERR79;
+            goto FAILED;
+            }    
+
+          if (ge)
+            code[1+LINK_SIZE] = ((PCRE2_MAJOR > major) ||
+              (PCRE2_MAJOR == major && PCRE2_MINOR >= minor))?
+                OP_TRUE : OP_FALSE;
+          else     
+            code[1+LINK_SIZE] = (PCRE2_MAJOR == major && PCRE2_MINOR == minor)?
+              OP_TRUE : OP_FALSE;
+ 
+          ptr++;
+          skipbytes = 1;
+          break;  /* End of condition processing */
+          }  
+         
+        /* Check for a test for recursion in a named group. */
+
         if (*ptr == CHAR_R && ptr[1] == CHAR_AMPERSAND)
           {
           terminator = -1;
@@ -5338,11 +5401,13 @@ for (;; ptr++)
           }
 
         /* Similarly, check for the (?(DEFINE) "condition", which is always
-        false. */
+        false. During compilation we set OP_DEFINE to distinguish this from 
+        other OP_FALSE conditions so that it can be checked for having only one 
+        branch, but after that the opcode is changed to OP_FALSE. */
 
         else if (namelen == 6 && PRIV(strncmp_c8)(name, STRING_DEFINE, 6) == 0)
           {
-          code[1+LINK_SIZE] = OP_DEF;
+          code[1+LINK_SIZE] = OP_DEFINE;
           skipbytes = 1;
           }
 
@@ -6065,16 +6130,18 @@ for (;; ptr++)
       while (*tc != OP_KET);
 
       /* A DEFINE group is never obeyed inline (the "condition" is always
-      false). It must have only one branch. */
+      false). It must have only one branch. Having checked this, change the 
+      opcode to OP_FALSE. */
 
-      if (code[LINK_SIZE+1] == OP_DEF)
+      if (code[LINK_SIZE+1] == OP_DEFINE)
         {
         if (condcount > 1)
           {
           *errorcodeptr = ERR54;
           goto FAILED;
           }
-        bravalue = OP_DEF;   /* Just a flag to suppress char handling below */
+        code[LINK_SIZE+1] = OP_FALSE; 
+        bravalue = OP_DEFINE;   /* Just a flag to suppress char handling below */
         }
 
       /* A "normal" conditional group. If there is just one branch, we must not
@@ -6127,7 +6194,7 @@ for (;; ptr++)
     /* For a DEFINE group, required and first character settings are not
     relevant. */
 
-    if (bravalue == OP_DEF) break;
+    if (bravalue == OP_DEFINE) break;
 
     /* Handle updating of the required and first characters for other types of
     group. Update for normal brackets of all kinds, and conditions with two
@@ -7011,7 +7078,8 @@ do {
        case OP_DNCREF:
        case OP_RREF:
        case OP_DNRREF:
-       case OP_DEF:
+       case OP_FALSE:
+       case OP_TRUE:
        return FALSE;
 
        default:     /* Assertion */
@@ -7414,6 +7482,10 @@ while (ptr[skipatstart] == CHAR_LEFT_PARENTHESIS &&
         cb.external_options |= p->value;
         break;
         
+        case PSO_FLG:
+        setflags |= p->value;
+        break;   
+
         case PSO_NL:
         newline = p->value;
         setflags |= PCRE2_NL_SET; 

src/pcre2_dfa_match.c

@@ -177,12 +177,12 @@ static const uint8_t coptable[] = {
   0, 0, 0, 0, 0,                 /* SBRA, SBRAPOS, SCBRA, SCBRAPOS, SCOND  */
   0, 0,                          /* CREF, DNCREF                           */
   0, 0,                          /* RREF, DNRREF                           */
-  0,                             /* DEF                                    */
+  0, 0,                          /* FALSE, TRUE                            */
   0, 0, 0,                       /* BRAZERO, BRAMINZERO, BRAPOSZERO        */
   0, 0, 0,                       /* MARK, PRUNE, PRUNE_ARG                 */
   0, 0, 0, 0,                    /* SKIP, SKIP_ARG, THEN, THEN_ARG         */
   0, 0, 0, 0,                    /* COMMIT, FAIL, ACCEPT, ASSERT_ACCEPT    */
-  0, 0                           /* CLOSE, SKIPZERO  */
+  0, 0, 0                        /* CLOSE, SKIPZERO, DEFINE                */
 };
 
 /* This table identifies those opcodes that inspect a character. It is used to
@@ -249,12 +249,12 @@ static const uint8_t poptable[] = {
   0, 0, 0, 0, 0,                 /* SBRA, SBRAPOS, SCBRA, SCBRAPOS, SCOND  */
   0, 0,                          /* CREF, DNCREF                           */
   0, 0,                          /* RREF, DNRREF                           */
-  0,                             /* DEF                                    */
+  0, 0,                          /* FALSE, TRUE                            */
   0, 0, 0,                       /* BRAZERO, BRAMINZERO, BRAPOSZERO        */
   0, 0, 0,                       /* MARK, PRUNE, PRUNE_ARG                 */
   0, 0, 0, 0,                    /* SKIP, SKIP_ARG, THEN, THEN_ARG         */
   0, 0, 0, 0,                    /* COMMIT, FAIL, ACCEPT, ASSERT_ACCEPT    */
-  0, 0                           /* CLOSE, SKIPZERO                        */
+  0, 0, 0                        /* CLOSE, SKIPZERO, DEFINE                */
 };
 
 /* These 2 tables allow for compact code for testing for \D, \d, \S, \s, \W,
@@ -2642,9 +2642,14 @@ for (;;)
 
         /* The DEFINE condition is always false */
 
-        if (condcode == OP_DEF)
+        if (condcode == OP_FALSE)
           { ADD_ACTIVE(state_offset + codelink + LINK_SIZE + 1, 0); }
           
+        /* There is also an always-true condition */
+
+        if (condcode == OP_TRUE)
+          { ADD_ACTIVE(state_offset + LINK_SIZE + 2 + IMM2_SIZE, 0); }
+
         /* The only supported version of OP_RREF is for the value RREF_ANY,
         which means "test if in any recursion". We can't test for specifically
         recursed groups. */
@@ -3115,6 +3120,24 @@ if (re->magic_number != MAGIC_NUMBER)
 if ((re->flags & PCRE2_MODE_MASK) != PCRE2_CODE_UNIT_WIDTH/8)
   return PCRE2_ERROR_BADMODE;
 
+/* PCRE2_NOTEMPTY and PCRE2_NOTEMPTY_ATSTART are match-time flags in the 
+options variable for this function. Users of PCRE2 who are not calling the 
+function directly would like to have a way of setting these flags, in the same 
+way that they can set pcre2_compile() flags like PCRE2_NO_AUTOPOSSESS with
+constructions like (*NO_AUTOPOSSESS). To enable this, (*NOTEMPTY) and 
+(*NOTEMPTY_ATSTART) set bits in the pattern's "flag" function which can now be 
+transferred to the options for this function. The bits are guaranteed to be 
+adjacent, but do not have the same values. This bit of Boolean trickery assumes 
+that the match-time bits are not more significant than the flag bits. If by 
+accident this is not the case, a compile-time division by zero error will 
+occur. */
+
+#define FF (PCRE2_NOTEMPTY_SET|PCRE2_NE_ATST_SET) 
+#define OO (PCRE2_NOTEMPTY|PCRE2_NOTEMPTY_ATSTART)
+options |= (re->flags & FF) / ((FF & -FF) / (OO & -OO));
+#undef FF
+#undef OO
+
 /* A NULL match context means "use a default context" */
 
 if (mcontext == NULL)

src/pcre2_error.c

@@ -158,6 +158,7 @@ static const char compile_error_texts[] =
   "name is too long in (*MARK), (*PRUNE), (*SKIP), or (*THEN)\0"
   "character code point value in \\u.... sequence is too large\0"
   "digits missing in \\x{} or \\o{}\0"
+  "syntax error in (?(VERSION condition\0"  
   ;
 
 /* Match-time and UTF error texts are in the same format. */

src/pcre2_internal.h

@@ -532,6 +532,8 @@ bytes in a code unit in that mode. */
 #define PCRE2_MATCH_EMPTY   0x00002000  /* pattern can match empty string */
 #define PCRE2_BSR_SET       0x00004000  /* BSR was set in the pattern */
 #define PCRE2_NL_SET        0x00008000  /* newline was set in the pattern */
+#define PCRE2_NOTEMPTY_SET  0x00010000  /* (*NOTEMPTY) used        ) keep */
+#define PCRE2_NE_ATST_SET   0x00020000  /* (*NOTEMPTY_ATSTART) used) together */
 
 #define PCRE2_MODE_MASK     (PCRE2_MODE8 | PCRE2_MODE16 | PCRE2_MODE32)
 
@@ -895,6 +897,7 @@ a positive value. */
 #define STRING_xdigit               "xdigit"
 
 #define STRING_DEFINE               "DEFINE"
+#define STRING_VERSION              "VERSION"
 #define STRING_WEIRD_STARTWORD      "[:<:]]"
 #define STRING_WEIRD_ENDWORD        "[:>:]]"
 
@@ -912,6 +915,8 @@ a positive value. */
 #define STRING_UCP_RIGHTPAR               "UCP)"
 #define STRING_NO_AUTO_POSSESS_RIGHTPAR   "NO_AUTO_POSSESS)"
 #define STRING_NO_START_OPT_RIGHTPAR      "NO_START_OPT)"
+#define STRING_NOTEMPTY_RIGHTPAR          "NOTEMPTY)"
+#define STRING_NOTEMPTY_ATSTART_RIGHTPAR  "NOTEMPTY_ATSTART)"
 #define STRING_LIMIT_MATCH_EQ             "LIMIT_MATCH="
 #define STRING_LIMIT_RECURSION_EQ         "LIMIT_RECURSION="
 
@@ -1161,6 +1166,7 @@ only. */
 #define STRING_xdigit               STR_x STR_d STR_i STR_g STR_i STR_t
 
 #define STRING_DEFINE               STR_D STR_E STR_F STR_I STR_N STR_E
+#define STRING_VERSION              STR_V STR_E STR_R STR_S STR_I STR_O STR_N
 #define STRING_WEIRD_STARTWORD      STR_LEFT_SQUARE_BRACKET STR_COLON STR_LESS_THAN_SIGN STR_COLON STR_RIGHT_SQUARE_BRACKET STR_RIGHT_SQUARE_BRACKET
 #define STRING_WEIRD_ENDWORD        STR_LEFT_SQUARE_BRACKET STR_COLON STR_GREATER_THAN_SIGN STR_COLON STR_RIGHT_SQUARE_BRACKET STR_RIGHT_SQUARE_BRACKET
 
@@ -1178,6 +1184,8 @@ only. */
 #define STRING_UCP_RIGHTPAR               STR_U STR_C STR_P STR_RIGHT_PARENTHESIS
 #define STRING_NO_AUTO_POSSESS_RIGHTPAR   STR_N STR_O STR_UNDERSCORE STR_A STR_U STR_T STR_O STR_UNDERSCORE STR_P STR_O STR_S STR_S STR_E STR_S STR_S STR_RIGHT_PARENTHESIS
 #define STRING_NO_START_OPT_RIGHTPAR      STR_N STR_O STR_UNDERSCORE STR_S STR_T STR_A STR_R STR_T STR_UNDERSCORE STR_O STR_P STR_T STR_RIGHT_PARENTHESIS
+#define STRING_NOTEMPTY_RIGHTPAR          STR_N STR_O STR_T STR_E STR_M STR_P STR_T STR_Y STR_RIGHT_PARENTHESIS
+#define STRING_NOTEMPTY_ATSTART_RIGHTPAR  STR_N STR_O STR_T STR_E STR_M STR_P STR_T STR_Y STR_UNDERSCORE STR_A STR_T STR_S STR_T STR_A STR_R STR_T STR_RIGHT_PARENTHESIS
 #define STRING_LIMIT_MATCH_EQ             STR_L STR_I STR_M STR_I STR_T STR_UNDERSCORE STR_M STR_A STR_T STR_C STR_H STR_EQUALS_SIGN
 #define STRING_LIMIT_RECURSION_EQ         STR_L STR_I STR_M STR_I STR_T STR_UNDERSCORE STR_R STR_E STR_C STR_U STR_R STR_S STR_I STR_O STR_N STR_EQUALS_SIGN
 
@@ -1517,39 +1525,47 @@ enum {
   OP_DNCREF,         /* 142 Used to point to duplicate names as a condition */
   OP_RREF,           /* 143 Used to hold a recursion number as condition */
   OP_DNRREF,         /* 144 Used to point to duplicate names as a condition */
-  OP_DEF,            /* 145 The DEFINE condition */
+  OP_FALSE,          /* 145 Always false (used by DEFINE and VERSION) */
+  OP_TRUE,           /* 146 Always true (used by VERSION) */
 
-  OP_BRAZERO,        /* 146 These two must remain together and in this */
+  OP_BRAZERO,        /* 147 These two must remain together and in this */
-  OP_BRAMINZERO,     /* 147 order. */
+  OP_BRAMINZERO,     /* 148 order. */
-  OP_BRAPOSZERO,     /* 148 */
+  OP_BRAPOSZERO,     /* 149 */
 
   /* These are backtracking control verbs */
 
-  OP_MARK,           /* 149 always has an argument */
+  OP_MARK,           /* 150 always has an argument */
-  OP_PRUNE,          /* 150 */
+  OP_PRUNE,          /* 151 */
-  OP_PRUNE_ARG,      /* 151 same, but with argument */
+  OP_PRUNE_ARG,      /* 152 same, but with argument */
-  OP_SKIP,           /* 152 */
+  OP_SKIP,           /* 153 */
-  OP_SKIP_ARG,       /* 153 same, but with argument */
+  OP_SKIP_ARG,       /* 154 same, but with argument */
-  OP_THEN,           /* 154 */
+  OP_THEN,           /* 155 */
-  OP_THEN_ARG,       /* 155 same, but with argument */
+  OP_THEN_ARG,       /* 156 same, but with argument */
-  OP_COMMIT,         /* 156 */
+  OP_COMMIT,         /* 157 */
 
   /* These are forced failure and success verbs */
 
-  OP_FAIL,           /* 157 */
+  OP_FAIL,           /* 158 */
-  OP_ACCEPT,         /* 158 */
+  OP_ACCEPT,         /* 159 */
-  OP_ASSERT_ACCEPT,  /* 159 Used inside assertions */
+  OP_ASSERT_ACCEPT,  /* 160 Used inside assertions */
-  OP_CLOSE,          /* 160 Used before OP_ACCEPT to close open captures */
+  OP_CLOSE,          /* 161 Used before OP_ACCEPT to close open captures */
 
   /* This is used to skip a subpattern with a {0} quantifier */
 
-  OP_SKIPZERO,       /* 161 */
+  OP_SKIPZERO,       /* 162 */
+  
+  /* This is used to identify a DEFINE group during compilation so that it can
+  be checked for having only one branch. It is changed to OP_FALSE before 
+  compilation finishes. */
+  
+  OP_DEFINE,         /* 163 */
 
   /* This is not an opcode, but is used to check that tables indexed by opcode
   are the correct length, in order to catch updating errors - there have been
   some in the past. */
 
   OP_TABLE_LENGTH
+  
 };
 
 /* *** NOTE NOTE NOTE *** Whenever the list above is updated, the two macro
@@ -1594,12 +1610,13 @@ some cases doesn't actually use these names at all). */
   "Cond",                                                         \
   "SBra", "SBraPos", "SCBra", "SCBraPos",                         \
   "SCond",                                                        \
-  "Cond ref", "Cond dnref", "Cond rec", "Cond dnrec", "Cond def", \
+  "Cond ref", "Cond dnref", "Cond rec", "Cond dnrec",             \
+  "Cond false", "Cond true",                                      \
   "Brazero", "Braminzero", "Braposzero",                          \
   "*MARK", "*PRUNE", "*PRUNE", "*SKIP", "*SKIP",                  \
   "*THEN", "*THEN", "*COMMIT", "*FAIL",                           \
   "*ACCEPT", "*ASSERT_ACCEPT",                                    \
-  "Close", "Skip zero"
+  "Close", "Skip zero", "Define"
 
 
 /* This macro defines the length of fixed length operations in the compiled
@@ -1684,13 +1701,14 @@ in UTF-8 mode. The code that uses this table must know about such things. */
   1+LINK_SIZE,                   /* SCOND                                  */ \
   1+IMM2_SIZE, 1+2*IMM2_SIZE,    /* CREF, DNCREF                           */ \
   1+IMM2_SIZE, 1+2*IMM2_SIZE,    /* RREF, DNRREF                           */ \
-  1,                             /* DEF                                    */ \
+  1, 1,                          /* FALSE, TRUE                            */ \
   1, 1, 1,                       /* BRAZERO, BRAMINZERO, BRAPOSZERO        */ \
   3, 1, 3,                       /* MARK, PRUNE, PRUNE_ARG                 */ \
   1, 3,                          /* SKIP, SKIP_ARG                         */ \
   1, 3,                          /* THEN, THEN_ARG                         */ \
   1, 1, 1, 1,                    /* COMMIT, FAIL, ACCEPT, ASSERT_ACCEPT    */ \
-  1+IMM2_SIZE, 1                 /* CLOSE, SKIPZERO                        */
+  1+IMM2_SIZE, 1,                /* CLOSE, SKIPZERO                        */ \
+  1                              /* DEFINE                                 */ 
 
 /* A magic value for OP_RREF to indicate the "any recursion" condition. */
 

src/pcre2_match.c

@@ -1363,7 +1363,11 @@ for (;;)
         }
       break;
 
-      case OP_DEF:     /* DEFINE - always false */
+      case OP_FALSE:
+      break;
+      
+      case OP_TRUE:
+      condition = TRUE;
       break;   
 
       /* The condition is an assertion. Call match() to evaluate it - setting
@@ -6363,6 +6367,24 @@ if (re->magic_number != MAGIC_NUMBER)
 if ((re->flags & PCRE2_MODE_MASK) != PCRE2_CODE_UNIT_WIDTH/8)
   return PCRE2_ERROR_BADMODE;
   
+/* PCRE2_NOTEMPTY and PCRE2_NOTEMPTY_ATSTART are match-time flags in the 
+options variable for this function. Users of PCRE2 who are not calling the 
+function directly would like to have a way of setting these flags, in the same 
+way that they can set pcre2_compile() flags like PCRE2_NO_AUTOPOSSESS with
+constructions like (*NO_AUTOPOSSESS). To enable this, (*NOTEMPTY) and 
+(*NOTEMPTY_ATSTART) set bits in the pattern's "flag" function which can now be 
+transferred to the options for this function. The bits are guaranteed to be 
+adjacent, but do not have the same values. This bit of Boolean trickery assumes 
+that the match-time bits are not more significant than the flag bits. If by 
+accident this is not the case, a compile-time division by zero error will 
+occur. */
+
+#define FF (PCRE2_NOTEMPTY_SET|PCRE2_NE_ATST_SET) 
+#define OO (PCRE2_NOTEMPTY|PCRE2_NOTEMPTY_ATSTART)
+options |= (re->flags & FF) / ((FF & -FF) / (OO & -OO));
+#undef FF
+#undef OO
+
 /* A NULL match context means "use a default context" */
 
 if (mcontext == NULL)

src/pcre2_printint.c

@@ -422,8 +422,12 @@ for(;;)
       }
     break;
 
-    case OP_DEF:
+    case OP_FALSE:
-    fprintf(f, "    Cond def");
+    fprintf(f, "    Cond false");
+    break;
+
+    case OP_TRUE:
+    fprintf(f, "    Cond true");
     break;
 
     case OP_STARI:

src/pcre2_study.c

@@ -181,7 +181,8 @@ for (;;)
     case OP_DNCREF:
     case OP_RREF:
     case OP_DNRREF:
-    case OP_DEF:
+    case OP_FALSE:
+    case OP_TRUE:
     case OP_CALLOUT:
     case OP_SOD:
     case OP_SOM:
@@ -792,7 +793,8 @@ do
       case OP_COMMIT:
       case OP_COND:
       case OP_CREF:
-      case OP_DEF:
+      case OP_FALSE:
+      case OP_TRUE:
       case OP_DNCREF:
       case OP_DNREF:
       case OP_DNREFI:

testdata/testinput2

@@ -4070,4 +4070,40 @@ a random value. /Ix
 /abc(?=abcde)(?=ab)/allusedtext
     abcabcdefg
 
+/a*?b*?/
+    ab
+
+/(*NOTEMPTY)a*?b*?/
+    ab
+    ba
+    cb  
+
+/(*NOTEMPTY_ATSTART)a*?b*?/aftertext
+    ab
+    cdab 
+
+/(?(VERSION>=10.0)yes|no)/I
+    yesno
+    
+/(?(VERSION=8)yes){3}/BI,aftertext
+    yesno
+
+/(?(VERSION=8)yes|no){3}/I
+    yesnononoyes
+    ** Failers
+    yesno   
+
+/(?:(?<VERSION>abc)|xyz)(?(VERSION)yes|no)/I
+    abcyes
+    xyzno
+    ** Failers
+    abcno
+    xyzyes    
+
+/(?(VERSION<10)yes|no)/
+
+/(?(VERSION>10)yes|no)/
+
+/(?(VERSION>=10.0.0)yes|no)/
+
 # End of testinput2 

testdata/testinput6

@@ -4798,4 +4798,16 @@
 /abc(?=abcde)(?=ab)/allusedtext
     abcabcdefg
 
+/a*?b*?/
+    ab
+
+/(*NOTEMPTY)a*?b*?/
+    ab
+    ba
+    cb  
+
+/(*NOTEMPTY_ATSTART)a*?b*?/aftertext
+    ab
+    cdab 
+
 # End of testinput6

testdata/testoutput2

@@ -9357,7 +9357,7 @@ Partial match at offset 3: +ab
         Recurse
         Recurse
         Cond
-        Cond def
+        Cond false
         CBra 1
         <
         [^m]
@@ -9379,7 +9379,7 @@ Partial match at offset 3: +ab
         Recurse
         Recurse
         Cond
-        Cond def
+        Cond false
         CBra 1
         <
         [\x00-/:-\xff] (neg)
@@ -10095,7 +10095,7 @@ No match
         Recurse
         KetRpos
         Cond
-        Cond def
+        Cond false
         CBra 1
         Any
         Ket
@@ -10114,7 +10114,7 @@ No match
         Recurse
         KetRmax
         Cond
-        Cond def
+        Cond false
         CBra 1
         Any
         Ket
@@ -11058,7 +11058,7 @@ Matched, but too many substrings
 ------------------------------------------------------------------
         Bra
         Cond
-        Cond def
+        Cond false
         CBra 1
         a
         Ket
@@ -13720,4 +13720,84 @@ No match
  0: abcabcde
        >>>>>
 
+/a*?b*?/
+    ab
+ 0: 
+
+/(*NOTEMPTY)a*?b*?/
+    ab
+ 0: a
+    ba
+ 0: b
+    cb  
+ 0: b
+
+/(*NOTEMPTY_ATSTART)a*?b*?/aftertext
+    ab
+ 0: a
+ 0+ b
+    cdab 
+ 0: 
+ 0+ dab
+
+/(?(VERSION>=10.0)yes|no)/I
+Capturing subpattern count = 0
+Subject length lower bound = 2
+    yesno
+ 0: yes
+    
+/(?(VERSION=8)yes){3}/BI,aftertext
+------------------------------------------------------------------
+        Bra
+        Cond
+        Cond false
+        yes
+        Ket
+        Ket
+        End
+------------------------------------------------------------------
+Capturing subpattern count = 0
+May match empty string
+Subject length lower bound = 0
+    yesno
+ 0: 
+ 0+ yesno
+
+/(?(VERSION=8)yes|no){3}/I
+Capturing subpattern count = 0
+Subject length lower bound = 6
+    yesnononoyes
+ 0: nonono
+    ** Failers
+No match
+    yesno   
+No match
+
+/(?:(?<VERSION>abc)|xyz)(?(VERSION)yes|no)/I
+Capturing subpattern count = 1
+Named capturing subpatterns:
+  VERSION   1
+Starting code units: a x 
+Subject length lower bound = 5
+    abcyes
+ 0: abcyes
+ 1: abc
+    xyzno
+ 0: xyzno
+    ** Failers
+No match
+    abcno
+No match
+    xyzyes    
+No match
+
+/(?(VERSION<10)yes|no)/
+Failed: error 179 at offset 10: syntax error in (?(VERSION condition
+
+/(?(VERSION>10)yes|no)/
+Failed: error 179 at offset 11: syntax error in (?(VERSION condition
+
+/(?(VERSION>=10.0.0)yes|no)/
+Failed: error 179 at offset 16: syntax error in (?(VERSION condition
+
 # End of testinput2 

testdata/testoutput6

@@ -7689,4 +7689,28 @@ Matched, but offsets vector is too small to show all matches
  0: abcabcde
        >>>>>
 
+/a*?b*?/
+    ab
+ 0: ab
+ 1: a
+ 2: 
+
+/(*NOTEMPTY)a*?b*?/
+    ab
+ 0: ab
+ 1: a
+    ba
+ 0: b
+    cb  
+ 0: b
+
+/(*NOTEMPTY_ATSTART)a*?b*?/aftertext
+    ab
+ 0: ab
+ 0+ 
+ 1: a
+    cdab 
+ 0: 
+ 0+ dab
+
 # End of testinput6