Merge cherrypicks of [3012829, 3012750, 3012751, 3012600, 3012601, 3012602, 3012603, 3012849, 3012850, 3012869, 3012870, 3012871, 3012872, 3012873, 3012630, 3012631, 3012632, 3012633, 3012634, 3012752, 3012753, 3012604, 3012605, 3012606, 3012929] into oc-r2-release

Change-Id: I0cce67142c22c9a6ca5d9f3dbb422f499fd89274
diff --git a/libutils/Unicode.cpp b/libutils/Unicode.cpp
index 5fd9155..6cff0f4 100644
--- a/libutils/Unicode.cpp
+++ b/libutils/Unicode.cpp
@@ -180,7 +180,15 @@
     size_t ret = 0;
     const char32_t *end = src + src_len;
     while (src < end) {
-        ret += utf32_codepoint_utf8_length(*src++);
+        size_t char_len = utf32_codepoint_utf8_length(*src++);
+        if (SSIZE_MAX - char_len < ret) {
+            // If this happens, we would overflow the ssize_t type when
+            // returning from this function, so we cannot express how
+            // long this string is in an ssize_t.
+            android_errorWriteLog(0x534e4554, "37723026");
+            return -1;
+        }
+        ret += char_len;
     }
     return ret;
 }
@@ -440,14 +448,23 @@
     size_t ret = 0;
     const char16_t* const end = src + src_len;
     while (src < end) {
+        size_t char_len;
         if ((*src & 0xFC00) == 0xD800 && (src + 1) < end
                 && (*(src + 1) & 0xFC00) == 0xDC00) {
             // surrogate pairs are always 4 bytes.
-            ret += 4;
+            char_len = 4;
             src += 2;
         } else {
-            ret += utf32_codepoint_utf8_length((char32_t) *src++);
+            char_len = utf32_codepoint_utf8_length((char32_t)*src++);
         }
+        if (SSIZE_MAX - char_len < ret) {
+            // If this happens, we would overflow the ssize_t type when
+            // returning from this function, so we cannot express how
+            // long this string is in an ssize_t.
+            android_errorWriteLog(0x534e4554, "37723026");
+            return -1;
+        }
+        ret += char_len;
     }
     return ret;
 }