Clarify some bit-shifting casts

src/libmdb/file.c

@@ -381,7 +381,7 @@ static ssize_t _mdb_read_pg(MdbHandle *mdb, void *pg_buf, unsigned long pg)
 	 */
 	if (pg != 0 && mdb->f->db_key != 0)
 	{
-		guint32 tmp_key_i = mdb->f->db_key ^ pg;
+		uint32_t tmp_key_i = mdb->f->db_key ^ pg;
 		unsigned char tmp_key[4] = {
 			tmp_key_i & 0xFF, (tmp_key_i >> 8) & 0xFF,
 			(tmp_key_i >> 16) & 0xFF, (tmp_key_i >> 24) & 0xFF };
@@ -414,7 +414,7 @@ unsigned char mdb_pg_get_byte(MdbHandle *mdb, int offset)
 int mdb_get_int16(void *buf, int offset)
 {
     unsigned char *u8_buf = (unsigned char *)buf + offset;
-    return u8_buf[0] + (u8_buf[1] << 8);
+    return ((uint32_t)u8_buf[0] << 0) + ((uint32_t)u8_buf[1] << 8);
 }
 int mdb_pg_get_int16(MdbHandle *mdb, int offset)
 {
@@ -426,12 +426,20 @@ int mdb_pg_get_int16(MdbHandle *mdb, int offset)
 long mdb_get_int32_msb(void *buf, int offset)
 {
     unsigned char *u8_buf = (unsigned char *)buf + offset;
-    return (u8_buf[0] << 24) + (u8_buf[1] << 16) + (u8_buf[2] << 8) + u8_buf[3];
+    return
+        ((uint32_t)u8_buf[0] << 24) +
+        ((uint32_t)u8_buf[1] << 16) +
+        ((uint32_t)u8_buf[2] << 8) +
+        ((uint32_t)u8_buf[3] << 0);
 }
 long mdb_get_int32(void *buf, int offset)
 {
     unsigned char *u8_buf = (unsigned char *)buf + offset;
-    return u8_buf[0] + (u8_buf[1] << 8) + (u8_buf[2] << 16) + (u8_buf[3] << 24);
+    return
+        ((uint32_t)u8_buf[0] << 0) +
+        ((uint32_t)u8_buf[1] << 8) +
+        ((uint32_t)u8_buf[2] << 16) +
+        ((uint32_t)u8_buf[3] << 24);
 }
 long mdb_pg_get_int32(MdbHandle *mdb, int offset)
 {
@@ -442,9 +450,12 @@ long mdb_pg_get_int32(MdbHandle *mdb, int offset)
 
 float mdb_get_single(void *buf, int offset)
 {
-	union {guint32 g; float f;} f;
+	union {uint32_t g; float f;} f;
     unsigned char *u8_buf = (unsigned char *)buf + offset;
-    f.g = u8_buf[0] + (u8_buf[1] << 8) + (u8_buf[2] << 16) + (u8_buf[3] << 24);
+    f.g = ((uint32_t)u8_buf[0] << 0) +
+        ((uint32_t)u8_buf[1] << 8) +
+        ((uint32_t)u8_buf[2] << 16) +
+        ((uint32_t)u8_buf[3] << 24);
 	return f.f;
 }
 float mdb_pg_get_single(MdbHandle *mdb, int offset)
@@ -456,18 +467,19 @@ float mdb_pg_get_single(MdbHandle *mdb, int offset)
 
 double mdb_get_double(void *buf, int offset)
 {
-	union {guint64 g; double d;} d;
+	union {uint64_t g; double d;} d;
     unsigned char *u8_buf = (unsigned char *)buf + offset;
-    d.g = ((guint64)u8_buf[0]) +
+    d.g = ((uint64_t)u8_buf[0] << 0) +
-           ((guint64)u8_buf[1] << 8) +
+           ((uint64_t)u8_buf[1] << 8) +
-           ((guint64)u8_buf[2] << 16) +
+           ((uint64_t)u8_buf[2] << 16) +
-           ((guint64)u8_buf[3] << 24) +
+           ((uint64_t)u8_buf[3] << 24) +
-           ((guint64)u8_buf[4] << 32) +
+           ((uint64_t)u8_buf[4] << 32) +
-           ((guint64)u8_buf[5] << 40) +
+           ((uint64_t)u8_buf[5] << 40) +
-           ((guint64)u8_buf[6] << 48) +
+           ((uint64_t)u8_buf[6] << 48) +
-           ((guint64)u8_buf[7] << 56);
+           ((uint64_t)u8_buf[7] << 56);
 	return d.d;
 }
+
 double mdb_pg_get_double(MdbHandle *mdb, int offset)
 {
 	if (offset <0 || offset+8 > mdb->fmt->pg_size) return -1;
@@ -475,7 +487,6 @@ double mdb_pg_get_double(MdbHandle *mdb, int offset)
 	return mdb_get_double(mdb->pg_buf, offset);
 }
 
-
 int 
 mdb_set_pos(MdbHandle *mdb, int pos)
 {