Merge remote-tracking branch 'upstream/master' into list_count

3 files changed, 31 insertions, 2 deletions

diff --git a/py/objstr.c b/py/objstr.c
index 59547e3cd6..54e6f37705 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -41,9 +41,20 @@ mp_obj_t str_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
                 int len = strlen(lhs_str);
                 if (start < 0) {
                     start = len + start;
+                    if (start < 0) {
+                        start = 0;
+                    }
+                } else if (start > len) {
+                    start = len;
                 }
                 if (stop <= 0) {
                     stop = len + stop;
+                    // CPython returns empty string in such case
+                    if (stop < 0) {
+                        stop = start;
+                    }
+                } else if (stop > len) {
+                    stop = len;
                 }
                 return mp_obj_new_str(qstr_from_strn_copy(lhs_str + start, stop - start));
 #endif
diff --git a/stm/storage.c b/stm/storage.c
index 6878de22e6..daee4adb5e 100644
--- a/stm/storage.c
+++ b/stm/storage.c
@@ -49,6 +49,18 @@ static uint8_t *cache_get_addr_for_write(uint32_t flash_addr) {
     return (uint8_t*)CACHE_MEM_START_ADDR + flash_addr - flash_sector_start;
 }
 
+static uint8_t *cache_get_addr_for_read(uint32_t flash_addr) {
+    uint32_t flash_sector_start;
+    uint32_t flash_sector_size;
+    uint32_t flash_sector_id = flash_get_sector_info(flash_addr, &flash_sector_start, &flash_sector_size);
+    if (cache_flash_sector_id == flash_sector_id) {
+        // in cache, copy from there
+        return (uint8_t*)CACHE_MEM_START_ADDR + flash_addr - flash_sector_start;
+    }
+    // not in cache, copy straight from flash
+    return (uint8_t*)flash_addr;
+}
+
 void storage_init(void) {
     if (!is_initialised) {
         cache_flash_sector_id = 0;
@@ -131,8 +143,9 @@ bool storage_read_block(uint8_t *dest, uint32_t block) {
         return true;
 
     } else if (FLASH_PART1_START_BLOCK <= block && block < FLASH_PART1_START_BLOCK + FLASH_PART1_NUM_BLOCKS) {
-        // non-MBR block, just copy straight from flash
-        uint8_t *src = (uint8_t*)FLASH_MEM_START_ADDR + (block - FLASH_PART1_START_BLOCK) * BLOCK_SIZE;
+        // non-MBR block, get data from flash memory, possibly via cache
+        uint32_t flash_addr = FLASH_MEM_START_ADDR + (block - FLASH_PART1_START_BLOCK) * BLOCK_SIZE;
+        uint8_t *src = cache_get_addr_for_read(flash_addr);
         memcpy(dest, src, BLOCK_SIZE);
         return true;
 
diff --git a/tests/basics/tests/slice-bstr1.py b/tests/basics/tests/slice-bstr1.py
index 0bed959141..74dbc20617 100644
--- a/tests/basics/tests/slice-bstr1.py
+++ b/tests/basics/tests/slice-bstr1.py
@@ -22,6 +22,11 @@ print(b"123"[0:])
 print(b"123"[:0])
 print(b"123"[:-3])
 print(b"123"[:-4])
+# Range check testing, don't segfault, please ;-)
+print(b"123"[:1000000])
+print(b"123"[1000000:])
+print(b"123"[:-1000000])
+print(b"123"[-1000000:])
 # No IndexError!
 print(b""[1:1])
 print(b""[-1:-1])