Fix capturing in conditional negative assertions ended with (*ACCEPT).

ChangeLog

@@ -29,7 +29,10 @@ bugs were never in fully released code, but are noted here for the record.
       vector on the stack is not big enough to handle at least 10 frames. 
       Fixes oss-fuzz issue 783. 
       
-  (c) Handling of (*VERB)s in recursions was wrong in some cases. 
+  (c) Handling of (*VERB)s in recursions was wrong in some cases.
+  
+  (d) Captures in negative assertions that were used as conditions were not
+      happening if the assertion matched via (*ACCEPT).   
       
 2. Now that pcre2_match() no longer uses recursive function calls (see above),
 the "match limit recursion" value seems misnamed. It still exists, and limits 

src/pcre2_match.c

@@ -5332,17 +5332,14 @@ fprintf(stderr, "++ op=%d\n", *Fecode);
 
         switch(rrc)
           {
-          case MATCH_ACCEPT:
+          case MATCH_ACCEPT:  /* Save captures */
-          if (Lpositive)      /* Save captures if a positive assertion */
+          memcpy(Fovector,
-            {
+                (char *)assert_accept_frame + offsetof(heapframe, ovector),
-            memcpy(Fovector,
+                assert_accept_frame->offset_top * sizeof(PCRE2_SIZE));
-                  (char *)assert_accept_frame + offsetof(heapframe, ovector),
+          Foffset_top = assert_accept_frame->offset_top;
-                  assert_accept_frame->offset_top * sizeof(PCRE2_SIZE));
-            Foffset_top = assert_accept_frame->offset_top;
-            }
 
-          /* Fall through. In the case of a match for a positive assertion, the
+          /* Fall through. In the case of a match, the captures have already
-          captures have already been put into the current frame. */
+          been put into the current frame. */
 
           case MATCH_MATCH:
           condition = Lpositive;   /* TRUE for positive assertion */

testdata/testinput1

@@ -5905,4 +5905,16 @@ ef) x/x,mark
 /^(.|(.)(?1)?\2)$/
     abcba
     
+/^(?(?=(a))abc|def)/
+    abc
+
+/^(?(?!(a))def|abc)/
+    abc
+
+/^(?(?=(a)(*ACCEPT))abc|def)/
+    abc
+
+/^(?(?!(a)(*ACCEPT))def|abc)/
+    abc
+
 # End of testinput1 

testdata/testoutput1

@@ -9467,4 +9467,24 @@ No match
  1: abcba
  2: a
     
+/^(?(?=(a))abc|def)/
+    abc
+ 0: abc
+ 1: a
+
+/^(?(?!(a))def|abc)/
+    abc
+ 0: abc
+ 1: a
+
+/^(?(?=(a)(*ACCEPT))abc|def)/
+    abc
+ 0: abc
+ 1: a
+
+/^(?(?!(a)(*ACCEPT))def|abc)/
+    abc
+ 0: abc
+ 1: a
+
 # End of testinput1