[FFmpeg-devel] [PATCH] lavu/common: make GET_UTF8 less broken

[Stefano Sabatini]

Avoid to process data and push the pointer forward in case as soon as an
error is encountered.

For example if the error is an assignment, this will allow to exit the
while block as soon as possible.
---
 libavutil/common.h | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/libavutil/common.h b/libavutil/common.h
index 9f0f998..58f7e42 100644
--- a/libavutil/common.h
+++ b/libavutil/common.h
@@ -300,14 +300,20 @@ static av_always_inline av_const int av_popcount64_c(uint64_t x)
     val= GET_BYTE;\
     {\
         uint32_t top = (val & 128) >> 1;\
-        if ((val & 0xc0) == 0x80 || val >= 0xFE)\
+        int err = 0;\
+        if ((val & 0xc0) == 0x80 || val >= 0xFE) {\
+            err = 1;\
             ERROR\
-        while (val & top) {\
+        }\
+        while (!err && (val & top)) {\
             int tmp= GET_BYTE - 128;\
-            if(tmp>>6)\
+            if (tmp>>6) {\
+                err = 1;\
                 ERROR\
-            val= (val<<6) + tmp;\
-            top <<= 5;\
+            } else {\
+                val x = (val<<6) + tmp;\
+                top <<= 5;\
+            }\
         }\
         val &= (top << 1) - 1;\
     }
-- 
1.8.1.2