Opened 12 years ago
Closed 12 years ago
Last modified 12 years ago
#10478 closed Patch - Bug Fix (fixed)
Commercial flagging array initialization issue
Reported by: | Owned by: | cpinkham | |
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Priority: | minor | Milestone: | 0.25 |
Component: | MythTV - Mythcommflag | Version: | Master Head |
Severity: | medium | Keywords: | |
Cc: | Ticket locked: | no |
Description
clang detected in mythtv/programs/mythcommflag/ClassicCommDetector.cpp a warning of the form "warning: argument to 'sizeof' in 'memset' call is the same expression as the destination; did you mean to dereference it?" from the following code fragment:
memset(sc_histogram, 0, sizeof(sc_histogram));
My guess from reading the code is that the intent was to zero the entire array (and not just the size of the pointer) more or less as:
memset(sc_histogram, 0, sizeof(*sc_histogram)*(seconds+1));
(patch attached)
However, depending on what memory was allocated (and what its state was) this could substantially change (improve/worsen) commercial detection results. I presume that the SME for commercial flagging needs to carefully evaluate with their test cases the results of this proposed change.
Thanks.
Gary
Attachments (1)
Change History (5)
Changed 12 years ago by
Attachment: | ClassicCommDetector_cpp.diff added |
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comment:1 Changed 12 years ago by
Component: | MythTV - General → MythTV - Mythcommflag |
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Milestone: | unknown → 0.25 |
Owner: | set to cpinkham |
Version: | Unspecified → Master Head |
comment:2 Changed 12 years ago by
Resolution: | → fixed |
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Status: | new → closed |
comment:3 Changed 12 years ago by
The patch as modified still will only zero the first int of sc_histogram due to the (presumably) extra sizeof operand.
Did you perhaps mean to write:
memset(sc_histogram, 0, (seconds+1)*sizeof(int));
rather than:
memset(sc_histogram, 0, sizeof((seconds+1)*sizeof(int)));
comment:4 Changed 12 years ago by
Fix a stupid brain-o
Thanks again to Gary for finding this.
Refs #10478
Branch: master Changeset: 4c93463cabb5f26ab2ae773b355b3860895c1563
Fix initialization of histograms
Based on a patch from Gary Buhrmaster <gary.buhrmaster@…>
Fixes #10478