# [PATCH] xdiff/xprepare: initialise xdlclassifier_t cf in xdl_prepare_env() 4 messages from 2011-08-31 to 2011-09-02. Participants: Tay Ray Chuan, Junio C Hamano. Thread: https://gitlist.dev/t/28266 ## Tay Ray Chuan, 2011-08-31 04:48 Subject: [PATCH] xdiff/xprepare: initialise xdlclassifier_t cf in xdl_prepare_env() Message-ID: <1314766126-5060-1-git-send-email-rctay89@gmail.com> URL: https://gitlist.dev/e/1314766126-5060-1-git-send-email-rctay89%40gmail.com ``` Ensure that the xdl_free_classifier() call on xdlclassifier_t cf is safe even if xdl_init_classifier() isn't called. This may occur in the case where diff is run with --histogram and a call to, say, xdl_prepare_ctx() fails. Signed-off-by: Tay Ray Chuan --- This should go into 'rc/histogram-diff' in 'next'. xdiff/xprepare.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c index 620fc9a..4323596 100644 --- a/xdiff/xprepare.c +++ b/xdiff/xprepare.c @@ -239,6 +239,9 @@ int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, long enl1, enl2, sample; xdlclassifier_t cf; + cf.rchash = NULL; + cf.ncha.head = NULL; + /* * For histogram diff, we can afford a smaller sample size and * thus a poorer estimate of the number of lines, as the hash -- 1.7.6.1.706.gaa5cf ``` ## Junio C Hamano, 2011-08-31 17:02 Subject: Re: [PATCH] xdiff/xprepare: initialise xdlclassifier_t cf in xdl_prepare_env() Message-ID: <7vei01zf89.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7vei01zf89.fsf%40alter.siamese.dyndns.org In-Reply-To: <1314766126-5060-1-git-send-email-rctay89@gmail.com> ``` Tay Ray Chuan writes: > Ensure that the xdl_free_classifier() call on xdlclassifier_t cf is safe > even if xdl_init_classifier() isn't called. This may occur in the case > where diff is run with --histogram and a call to, say, xdl_prepare_ctx() > fails. > > Signed-off-by: Tay Ray Chuan Thanks. Did you find this by code inspection? > xdiff/xprepare.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c > index 620fc9a..4323596 100644 > --- a/xdiff/xprepare.c > +++ b/xdiff/xprepare.c > @@ -239,6 +239,9 @@ int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, > long enl1, enl2, sample; > xdlclassifier_t cf; > > + cf.rchash = NULL; > + cf.ncha.head = NULL; Would it be more appropriate to use memcpy(&cf, 0, sizeof(cf)) instead, so that we wouldn't have to worry about a similar breakage when a new field is added to "struct xdlclassifier" later? ``` ## Junio C Hamano, 2011-08-31 17:03 Subject: Re: [PATCH] xdiff/xprepare: initialise xdlclassifier_t cf in xdl_prepare_env() Message-ID: <7vaaapzf6f.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7vaaapzf6f.fsf%40alter.siamese.dyndns.org In-Reply-To: <7vei01zf89.fsf@alter.siamese.dyndns.org> ``` Junio C Hamano writes: > Tay Ray Chuan writes: > >> Ensure that the xdl_free_classifier() call on xdlclassifier_t cf is safe >> even if xdl_init_classifier() isn't called. This may occur in the case >> where diff is run with --histogram and a call to, say, xdl_prepare_ctx() >> fails. >> >> Signed-off-by: Tay Ray Chuan > > Thanks. Did you find this by code inspection? > >> xdiff/xprepare.c | 3 +++ >> 1 files changed, 3 insertions(+), 0 deletions(-) >> >> diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c >> index 620fc9a..4323596 100644 >> --- a/xdiff/xprepare.c >> +++ b/xdiff/xprepare.c >> @@ -239,6 +239,9 @@ int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, >> long enl1, enl2, sample; >> xdlclassifier_t cf; >> >> + cf.rchash = NULL; >> + cf.ncha.head = NULL; > > Would it be more appropriate to use memcpy(&cf, 0, sizeof(cf)) instead, so Oops, I meant memset(), obviously. > that we wouldn't have to worry about a similar breakage when a new field > is added to "struct xdlclassifier" later? ``` ## Tay Ray Chuan, 2011-09-02 07:09 Subject: [PATCH] xdiff/xprepare: initialise xdlclassifier_t cf in xdl_prepare_env() Message-ID: <1314947363-4596-1-git-send-email-rctay89@gmail.com> URL: https://gitlist.dev/e/1314947363-4596-1-git-send-email-rctay89%40gmail.com In-Reply-To: <7vaaapzf6f.fsf@alter.siamese.dyndns.org> ``` Ensure that the xdl_free_classifier() call on xdlclassifier_t cf is safe even if xdl_init_classifier() isn't called, which is the case when diff is run with --histogram. Signed-off-by: Tay Ray Chuan --- On Thu, Sep 1, 2011 at 1:02 AM, Junio C Hamano wrote: > Tay Ray Chuan writes: > >> Ensure that the xdl_free_classifier() call on xdlclassifier_t cf is safe >> even if xdl_init_classifier() isn't called. This may occur in the case >> where diff is run with --histogram and a call to, say, xdl_prepare_ctx() >> fails. >> >> Signed-off-by: Tay Ray Chuan > > Thanks. Did you find this by code inspection? If by "code inspection" you meant eye-balling, then yes. :) On Thu, Sep 1, 2011 at 1:03 AM, Junio C Hamano wrote: > Junio C Hamano writes: > [snip] >>> @@ -239,6 +239,9 @@ int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, >>>      long enl1, enl2, sample; >>>      xdlclassifier_t cf; >>> >>> +    cf.rchash = NULL; >>> +    cf.ncha.head = NULL; >> >> Would it be more appropriate to use memcpy(&cf, 0, sizeof(cf)) instead, so > > Oops, I meant memset(), obviously. Right, thanks. --- xdiff/xprepare.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c index 620fc9a..5b676b7 100644 --- a/xdiff/xprepare.c +++ b/xdiff/xprepare.c @@ -239,6 +239,8 @@ int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, long enl1, enl2, sample; xdlclassifier_t cf; + memset(&cf, 0, sizeof(cf)); + /* * For histogram diff, we can afford a smaller sample size and * thus a poorer estimate of the number of lines, as the hash -- 1.7.6.1.706.gaa5cf ```