311064 2026-03-29 22:51:08 -0700 Table with fixed-height cells and border-spacing doesn't respect specified height 2026-04-27 22:50:30 -0700 1 1 1 Unclassified WebKit Tables WebKit Nightly Build Unspecified Unspecified RESOLVED DUPLICATE 226002 InRadar P2 Normal --- 1 karlcow karlcow webkit-bug-importer zalan oldest_to_newest 2195002 0 karlcow 2026-03-29 22:51:08 -0700 A table with height: 500px, border-spacing: 0 50px, and two rows with fixed-height cells (td { height: 20px }) renders at 418px in Safari instead of the specified 500px. Chrome and Firefox both correctly render the table at 500px. The root cause is in RenderTableSection::distributeRemainingExtraLogicalHeight (RenderTableSection.cpp). The function distributes extra height proportionally using m_rowPos[totalRows] as the denominator, but this value includes the initial m_rowPos[0] offset which is set to vBorderSpacing() for the top section. The code has a FIXME acknowledging this: // FIXME: m_rowPos[totalRows] - m_rowPos[0] is the total rows' size. LayoutUnit totalRowSize = m_rowPos[totalRows]; The sum of all row-slice numerators in the loop equals m_rowPos[totalRows] - m_rowPos[0], which is less than the denominator m_rowPos[totalRows]. This means a fraction of the extra height proportional to m_rowPos[0] / m_rowPos[totalRows] is never distributed, leaving the table shorter than specified. For the test case: m_rowPos is [50, 120, 190]. The extra height to distribute is 500 - 190 = 310px. The sum of numerators is (120-50) + (190-120) = 140, but the denominator is 190. Only 310 * 140/190 ≈ 228px gets distributed, yielding a final height of 190 + 228 = 418px instead of 500px. The fix is to change the denominator to m_rowPos[totalRows] - m_rowPos[0], matching what the FIXME describes. Steps to Reproduce: 1. Create a table with height: 500px; border-spacing: 0 50px; border: none 2. Add two rows with td { height: 20px } 3. Compare table height across browsers Expected: Table renders at 500px (Chrome, Firefox behavior) Actual: Table renders at 418px in Safari 2195003 1 webkit-bug-importer 2026-03-29 22:51:14 -0700 <rdar://problem/173665148> 2195004 2 478838 karlcow 2026-03-29 22:52:41 -0700 Created attachment 478838 testcase 2195006 3 karlcow 2026-03-29 23:12:58 -0700 Pull request: https://github.com/WebKit/WebKit/pull/61659 2205249 4 karlcow 2026-04-27 22:50:30 -0700 *** This bug has been marked as a duplicate of bug 226002 *** 478838 2026-03-29 22:52:41 -0700 2026-03-29 22:52:41 -0700 testcase bug02-table-height-border-spacing.html text/html 1617 karlcow PCFET0NUWVBFIGh0bWw+CjxodG1sPgo8aGVhZD4KPG1ldGEgY2hhcnNldD0idXRmLTgiPgo8dGl0 bGU+VGFibGUgaGVpZ2h0IG5vdCByZXNwZWN0ZWQgd2l0aCBib3JkZXItc3BhY2luZyBhbmQgZml4 ZWQtaGVpZ2h0IGNlbGxzPC90aXRsZT4KPHN0eWxlPgogICN0YWJsZXRlc3QgewogICAgaGVpZ2h0 OiA1MDBweDsKICAgIHdpZHRoOiAyMDBweDsKICAgIGJvcmRlci1zcGFjaW5nOiAwIDUwcHg7CiAg ICBib3JkZXI6IG5vbmU7CiAgICBiYWNrZ3JvdW5kOiBvcmFuZ2U7CiAgfQogICN0YWJsZXRlc3Qg dGQgewogICAgaGVpZ2h0OiAyMHB4OwogICAgYmFja2dyb3VuZDogbGlnaHRibHVlOwogICAgcGFk ZGluZzogMDsKICB9Cjwvc3R5bGU+CjwvaGVhZD4KPGJvZHk+CjxoMz5UYWJsZSBoZWlnaHQgbm90 IHJlc3BlY3RlZCB3aXRoIGJvcmRlci1zcGFjaW5nIGFuZCBmaXhlZC1oZWlnaHQgY2VsbHM8L2gz Pgo8cD5UaGUgdGFibGUgaGFzIDxjb2RlPmhlaWdodDogNTAwcHg8L2NvZGU+IGFuZCA8Y29kZT5i b3JkZXItc3BhY2luZzogMCA1MHB4PC9jb2RlPgp3aXRoIHR3byBmaXhlZC1oZWlnaHQgY2VsbHMg KDxjb2RlPnRkIHsgaGVpZ2h0OiAyMHB4IH08L2NvZGU+KS4gVGhlIGV4dHJhIGhlaWdodApzaG91 bGQgYmUgZGlzdHJpYnV0ZWQgdG8gdGhlIHJvd3Mgc28gdGhlIHRhYmxlIHJlYWNoZXMgNTAwcHgu PC9wPgo8cD5PcmFuZ2UgYXJlYXMgYXJlIGJvcmRlci1zcGFjaW5nIGdhcHMuIElmIHRoZSB0YWJs ZSBpcyBzaG9ydGVyIHRoYW4gNTAwcHgsCnRoZSBleHRyYSBoZWlnaHQgZGlzdHJpYnV0aW9uIGlz IGJyb2tlbi48L3A+Cgo8dGFibGUgaWQ9InRhYmxldGVzdCI+CiAgPHRyPjx0ZD5Sb3cgMTwvdGQ+ PC90cj4KICA8dHI+PHRkPlJvdyAyPC90ZD48L3RyPgo8L3RhYmxlPgoKPHByZSBpZD0icmVzdWx0 Ij48L3ByZT4KCjxzY3JpcHQ+CmRvY3VtZW50LmFkZEV2ZW50TGlzdGVuZXIoIkRPTUNvbnRlbnRM b2FkZWQiLCAoKSA9PiB7CiAgY29uc3QgdGFibGUgPSBkb2N1bWVudC5nZXRFbGVtZW50QnlJZCgi dGFibGV0ZXN0Iik7CiAgY29uc3QgcmVzdWx0ID0gZG9jdW1lbnQuZ2V0RWxlbWVudEJ5SWQoInJl c3VsdCIpOwogIGNvbnN0IGFjdHVhbCA9IHRhYmxlLm9mZnNldEhlaWdodDsKICBjb25zdCBleHBl Y3RlZCA9IDUwMDsKICBjb25zdCBkaWZmID0gZXhwZWN0ZWQgLSBhY3R1YWw7CiAgbGV0IGluZm8g PSAiVGFibGUgc3BlY2lmaWVkIGhlaWdodDogIiArIGV4cGVjdGVkICsgInB4XG4iOwogIGluZm8g Kz0gIlRhYmxlIGFjdHVhbCBoZWlnaHQ6ICAgICIgKyBhY3R1YWwgKyAicHhcbiI7CiAgaW5mbyAr PSAiRGlmZmVyZW5jZTogICAgICAgICAgICAgIiArIGRpZmYgKyAicHhcbiI7CiAgaWYgKGRpZmYg PiAwKQogICAgaW5mbyArPSAiRkFJTDogVGFibGUgaXMgIiArIGRpZmYgKyAicHggc2hvcnRlciB0 aGFuIHNwZWNpZmllZC4iOwogIGVsc2UKICAgIGluZm8gKz0gIlBBU1M6IFRhYmxlIHJlc3BlY3Rz IHRoZSBzcGVjaWZpZWQgaGVpZ2h0LiI7CiAgcmVzdWx0LnRleHRDb250ZW50ID0gaW5mbzsKICBy ZXN1bHQuc3R5bGUuY29sb3IgPSBkaWZmID4gMCA/ICJyZWQiIDogImdyZWVuIjsKfSk7Cjwvc2Ny aXB0Pgo8L2JvZHk+CjwvaHRtbD4K