IO: fix short read when reading from pipe

src/common/io/io_unix.c

@@ -54,24 +54,20 @@ bool ffAppendFDBuffer(int fd, FFstrbuf* buffer)
     uint32_t free = ffStrbufGetFree(buffer);
 
     while(
-        (readed = read(fd, buffer->chars + buffer->length, free)) > 0 &&
-        (uint32_t) readed == free
+        (readed = read(fd, buffer->chars + buffer->length, free)) > 0
     ) {
         buffer->length += (uint32_t) readed;
-        ffStrbufEnsureFree(buffer, buffer->allocated - 1); // Doubles capacity every round. -1 for the null byte.
+        if((uint32_t) readed == free)
+            ffStrbufEnsureFree(buffer, buffer->allocated - 1); // Doubles capacity every round. -1 for the null byte.
         free = ffStrbufGetFree(buffer);
     }
 
-    // In case of failure, read returns -1. We don't want to substract the length of the buffer.
-    if(readed > 0)
-        buffer->length += (uint32_t) readed;
-
     buffer->chars[buffer->length] = '\0';
 
     ffStrbufTrimRight(buffer, '\n');
     ffStrbufTrimRight(buffer, ' ');
 
-    return readed >= 0;
+    return buffer->length > 0;
 }
 
 ssize_t ffReadFileData(const char* fileName, size_t dataSize, void* data)

src/common/io/io_windows.c

@@ -44,16 +44,14 @@ bool ffAppendFDBuffer(HANDLE handle, FFstrbuf* buffer)
     bool success;
     while(
         (success = !!ReadFile(handle, buffer->chars + buffer->length, free, &readed, NULL)) &&
-        (uint32_t) readed == free
+        readed > 0
     ) {
         buffer->length += (uint32_t) readed;
-        ffStrbufEnsureFree(buffer, buffer->allocated - 1); // Doubles capacity every round. -1 for the null byte.
+        if((uint32_t) readed == free)
+            ffStrbufEnsureFree(buffer, buffer->allocated - 1); // Doubles capacity every round. -1 for the null byte.
         free = ffStrbufGetFree(buffer);
     }
 
-    if(readed > 0)
-        buffer->length += (uint32_t) readed;
-
     buffer->chars[buffer->length] = '\0';
 
     ffStrbufTrimRight(buffer, '\n');