From: Peter Krempa Date: Thu, 4 Mar 2021 17:09:42 +0000 (+0100) Subject: virBufferAdd: Ensure that the buffer is initialized also when len == 0 X-Git-Tag: v7.2.0-rc1~209 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1553e7256701c725cf87bafa5d738da16f278c3d;p=thirdparty%2Flibvirt.git virBufferAdd: Ensure that the buffer is initialized also when len == 0 There's an optimization in virBufferAdd which returns early when the length of the added string is 0 (given that auto-indent is disabled). The optimization causes inconsistent behaviour between these two cases: virBufferAdd(buf, "", 0); // this doesn't initialize the buffer and virBufferAdd(buf, "", -1); //this initializes the buffer Since using an empty string is used to prime the buffer to an empty string it can be confusing. Remove the optimization. This fixes such a wrong initialization done in x86FeatureNames. Note that our code in many places expects that if no virBuffer APIs are used on a buffer object, then NULL should be retured, so we can't always prime the buffer to an empty string. Signed-off-by: Peter Krempa Reviewed-by: Ján Tomko --- diff --git a/src/util/virbuffer.c b/src/util/virbuffer.c index ebb4108b5d..b9ddf1f5c9 100644 --- a/src/util/virbuffer.c +++ b/src/util/virbuffer.c @@ -156,7 +156,7 @@ virBufferApplyIndent(virBufferPtr buf) void virBufferAdd(virBufferPtr buf, const char *str, int len) { - if (!str || !buf || (len == 0 && buf->indent == 0)) + if (!str || !buf) return; virBufferInitialize(buf);