regcomp.c: Change param to join_exact()

This changes a parameter to this function to instead of changing a running
total, return the actual value computed by the function; and it changes
the calling areas of code to compensate.

3 files changed, 21 insertions, 13 deletions

diff --git a/embed.fnc b/embed.fnc
index 3b81d3fc28..db08cfabaf 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -1889,7 +1889,7 @@ Es	|void	|regtail	|NN struct RExC_state_t *pRExC_state \
 Es	|SV *	|reg_scan_name	|NN struct RExC_state_t *pRExC_state \
 				|U32 flags
 Es	|U32	|join_exact	|NN struct RExC_state_t *pRExC_state \
-				|NN regnode *scan|NN I32 *min|U32 flags|NULLOK regnode *val|U32 depth
+				|NN regnode *scan|NN IV *min_change|U32 flags|NULLOK regnode *val|U32 depth
 EsRn	|char *	|regwhite	|NN struct RExC_state_t *pRExC_state \
 				|NN char *p
 Es	|char *	|nextchar	|NN struct RExC_state_t *pRExC_state
diff --git a/proto.h b/proto.h
index 60f191aa73..c9bccb9bd6 100644
--- a/proto.h
+++ b/proto.h
@@ -6350,12 +6350,12 @@ PERL_STATIC_INLINE void	S_invlist_trim(pTHX_ SV* const invlist)
 #define PERL_ARGS_ASSERT_INVLIST_TRIM	\
 	assert(invlist)
 
-STATIC U32	S_join_exact(pTHX_ struct RExC_state_t *pRExC_state, regnode *scan, I32 *min, U32 flags, regnode *val, U32 depth)
+STATIC U32	S_join_exact(pTHX_ struct RExC_state_t *pRExC_state, regnode *scan, IV *min_change, U32 flags, regnode *val, U32 depth)
 			__attribute__nonnull__(pTHX_1)
 			__attribute__nonnull__(pTHX_2)
 			__attribute__nonnull__(pTHX_3);
 #define PERL_ARGS_ASSERT_JOIN_EXACT	\
-	assert(pRExC_state); assert(scan); assert(min)
+	assert(pRExC_state); assert(scan); assert(min_change)
 
 STATIC I32	S_make_trie(pTHX_ struct RExC_state_t *pRExC_state, regnode *startbranch, regnode *first, regnode *last, regnode *tail, U32 word_count, U32 flags, U32 depth)
 			__attribute__nonnull__(pTHX_1)
diff --git a/regcomp.c b/regcomp.c
index 6917ee5520..100f73fad0 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -2506,14 +2506,12 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
 
 
 
-
-
-#define JOIN_EXACT(scan,min,flags) \
+#define JOIN_EXACT(scan,min_change,flags) \
     if (PL_regkind[OP(scan)] == EXACT) \
-        join_exact(pRExC_state,(scan),(min),(flags),NULL,depth+1)
+        join_exact(pRExC_state,(scan),(min_change),(flags),NULL,depth+1)
 
 STATIC U32
-S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, I32 *min, U32 flags,regnode *val, U32 depth) {
+S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, IV *min_change, U32 flags,regnode *val, U32 depth) {
     /* Merge several consecutive EXACTish nodes into one. */
     regnode *n = regnext(scan);
     U32 stringok = 1;
@@ -2595,6 +2593,8 @@ S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, I32 *min, U32 flags
 #define GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS	0x03B0
 #define UPSILON_D_T	GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS
 
+    *min_change = 0;
+
     /* Here, all the adjacent mergeable EXACTish nodes have been merged.  We
      * can now analyze for sequences of problematic code points.  (Prior to
      * this final joining, sequences could have been split over boundaries, and
@@ -2652,7 +2652,7 @@ S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, I32 *min, U32 flags
               if (((U8)t[-1] == 0xB9 && (U8)t[-2] == 0xCE) ||
                   ((U8)t[-1] == 0x85 && (U8)t[-2] == 0xCF))
 #endif
-                   *min -= 4;
+		    *min_change -= 4;
          }
     }
 
@@ -2769,10 +2769,11 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 
   fake_study_recurse:
     while ( scan && OP(scan) != END && scan < last ){
+        IV min_change = 0;
 	/* Peephole optimizer: */
 	DEBUG_STUDYDATA("Peep:", data,depth);
 	DEBUG_PEEP("Peep",scan,depth);
-        JOIN_EXACT(scan,&min,0);
+        JOIN_EXACT(scan,&min_change,0);
 
 	/* Follow the next-chain of the current node and optimize
 	   away all the NOTHINGs from it.  */
@@ -3286,9 +3287,16 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 		l = utf8_length(s, s + l);
 		uc = utf8_to_uvchr(s, NULL);
 	    }
-	    min += l;
-	    if (flags & SCF_DO_SUBSTR)
-		data->pos_min += l;
+	    min += l + min_change;
+            if (min < 0) {
+                min = 0;
+            }
+	    if (flags & SCF_DO_SUBSTR) {
+		data->pos_min += l + min_change;
+		if (data->pos_min < 0) {
+                    data->pos_min = 0;
+                }
+	    }
 	    if (flags & SCF_DO_STCLASS_AND) {
 		/* Check whether it is compatible with what we know already! */
 		int compat = 1;