Allocate zend_strings with correct size

For me (32bit) sizeof(zend_string) is 20, which means that the
char[1] array at the end is padded with three bytes. Thus allocating
based on sizeof(zend_string)-1 overallocates by those 3 padding bytes.

This commit fixes the allocation size, by using XtOffsetOf.

5 files changed, 8 insertions, 8 deletions

diff --git a/ext/opcache/ZendAccelerator.c b/ext/opcache/ZendAccelerator.c
index 84c397d7ab..11ca76e2f3 100644
--- a/ext/opcache/ZendAccelerator.c
+++ b/ext/opcache/ZendAccelerator.c
@@ -336,7 +336,7 @@ zend_string *accel_new_interned_string(zend_string *str TSRMLS_DC)
 		idx = Z_NEXT(p->val);
 	}
 
-	if (ZCSG(interned_strings_top) + ZEND_MM_ALIGNED_SIZE(sizeof(zend_string) + str->len) >=
+	if (ZCSG(interned_strings_top) + ZEND_MM_ALIGNED_SIZE(_STR_HEADER_SIZE + str->len + 1) >=
 	    ZCSG(interned_strings_end)) {
 	    /* no memory, return the same non-interned string */
 		return str;
@@ -348,7 +348,7 @@ zend_string *accel_new_interned_string(zend_string *str TSRMLS_DC)
 	ZCSG(interned_strings).nNumOfElements++;
 	p = ZCSG(interned_strings).arData + idx;
 	p->key = (zend_string*) ZCSG(interned_strings_top);
-	ZCSG(interned_strings_top) += ZEND_MM_ALIGNED_SIZE(sizeof(zend_string) + str->len);
+	ZCSG(interned_strings_top) += ZEND_MM_ALIGNED_SIZE(_STR_HEADER_SIZE + str->len + 1);
 	p->h = h;
 	GC_REFCOUNT(p->key) = 1;
 #if 1
diff --git a/ext/opcache/zend_persist.c b/ext/opcache/zend_persist.c
index ca2ad5150c..39a2aa4a7c 100644
--- a/ext/opcache/zend_persist.c
+++ b/ext/opcache/zend_persist.c
@@ -40,13 +40,13 @@
 			STR_RELEASE(str); \
 			str = new_str; \
 		} else { \
-	    	new_str = _zend_shared_memdup((void*)str, sizeof(zend_string) + (str)->len, 0 TSRMLS_CC); \
+	    	new_str = _zend_shared_memdup((void*)str, _STR_HEADER_SIZE + (str)->len + 1, 0 TSRMLS_CC); \
 			STR_RELEASE(str); \
 	    	str = new_str; \
 		} \
     } while (0)
 # define zend_accel_memdup_string(str) \
-	zend_accel_memdup(str, sizeof(zend_string) + (str)->len)
+	zend_accel_memdup(str, _STR_HEADER_SIZE + (str)->len + 1)
 # define zend_accel_store_interned_string(str) do { \
 		if (!IS_ACCEL_INTERNED(str)) { \
 			zend_accel_store_string(str); \
diff --git a/ext/opcache/zend_persist_calc.c b/ext/opcache/zend_persist_calc.c
index 6298fb1aa2..a347a34cf3 100644
--- a/ext/opcache/zend_persist_calc.c
+++ b/ext/opcache/zend_persist_calc.c
@@ -33,7 +33,7 @@
 
 #if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
 # define ADD_STRING(str) \
-		ADD_DUP_SIZE((str), sizeof(zend_string) + (str)->len)
+		ADD_DUP_SIZE((str), _STR_HEADER_SIZE + (str)->len + 1)
 # define ADD_INTERNED_STRING(str, do_free) do { \
 		if (!IS_ACCEL_INTERNED(str)) { \
 			zend_string *tmp = accel_new_interned_string(str TSRMLS_CC); \
diff --git a/ext/standard/php_smart_str.h b/ext/standard/php_smart_str.h
index a518fbfddf..5cc3a62137 100644
--- a/ext/standard/php_smart_str.h
+++ b/ext/standard/php_smart_str.h
@@ -45,11 +45,11 @@
 
 #ifdef SMART_STR_USE_REALLOC
 #define SMART_STR_DO_REALLOC(b, w) do {								\
-	(b)->s = erealloc((buf)->s, sizeof(zend_string) + (b)->a);		\
+	(b)->s = erealloc((buf)->s, _STR_HEADER_SIZE + (b)->a + 1);		\
 } while (0)
 #else
 #define SMART_STR_DO_REALLOC(b, w) do {								\
-	(b)->s = perealloc((b)->s, sizeof(zend_string) + (b)->a, (w));	\
+	(b)->s = perealloc((b)->s, _STR_HEADER_SIZE + (b)->a + 1, (w));	\
 } while (0)
 #endif
 
diff --git a/ext/standard/tests/strings/str_pad_variation5.phpt b/ext/standard/tests/strings/str_pad_variation5.phpt
index 0dee148650..d050ae80e8 100644
--- a/ext/standard/tests/strings/str_pad_variation5.phpt
+++ b/ext/standard/tests/strings/str_pad_variation5.phpt
@@ -24,7 +24,7 @@ echo "*** Testing str_pad() function: with large value for for 'pad_length' argu
 
 //defining '$input' argument
 $input = "Test string";
-$pad_length = PHP_INT_MAX - 20 + 1; /* sizeof(zend_string) is 20, 1 character is included in zend_string structure itself */
+$pad_length = PHP_INT_MAX - 16; /* zend_string header is 16 bytes */
 var_dump( str_pad($input, $pad_length) );
 
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