GetPictureCells and GetPictures functions don't support images with absolute path targets

[slashdotdash]

Description

The GetPictureCells and GetPictures functions don't appear to support images where the target attribute in the XML structure uses absolute paths.

For example the following xl/drawings/_rels/drawing1.xml.rels file which contains a Relationship with a Target attribute using an absolute path of "/xl/media/image1.jpg" does not work.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
    <Relationship Id="rId1"
        Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/image"
        Target="/xl/media/image1.jpg" />
</Relationships>

When the Target attribute is using a relative path of "../media/image1.jpg" it does work.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
    <Relationship Id="rId1"
        Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/image"
        Target="../media/image1.jpg" />
</Relationships>

Steps to reproduce the issue:

Use the attached TestGetPictureAbsolutePath.xls file which contains a single floating image and the following Go test which demonstrates a failure to detect any images when using GetPictureCells.

func TestGetPictureAbs(t *testing.T) {
	f, err := OpenFile(filepath.Join("test", "TestGetPictureAbsolutePath.xlsx"))
	assert.NoError(t, err)

	cells, err := f.GetPictureCells("Sheet1")
	assert.NoError(t, err)
	assert.Equal(t, []string{"A1"}, cells)
	assert.NoError(t, f.Close())

	pics, err := f.GetPictures("Sheet1", "A1")
	assert.NoError(t, err)
	assert.Len(t, pics, 1)
}

• TestGetPictureAbsolutePath.xlsx

Describe the results you received:

The above test fails:

$ go test -run TestGetPictureAbs
--- FAIL: TestGetPictureAbs (0.00s)
    picture_test.go:26: 
        	Error Trace:	picture_test.go:26
        	Error:      	Not equal: 
        	            	expected: []string{"A1"}
        	            	actual  : []string(nil)        	            
        	            	 
        	Test:       	TestGetPictureAbs
FAIL
exit status 1
FAIL	github.com/xuri/excelize/v2	0.300s

Describe the results you expected:

Using either relative or absolute paths for relationship targets should be acceptable.

Output of go version:

go version go1.21.6 darwin/arm64

Excelize version or commit ID:

excelize master @ 0447cb2

Environment details (OS, Microsoft Excel™ version, physical, etc.):

• macOS 14.6.1
• Microsoft Excel for Mac version 16.88

[slashdotdash]

Note I have been able to resolve the issue locally via a fork of the repo. Please see commit slashdotdash@801f110

I'm happy to submit a PR with the above changes however I am not sure whether they follow the preferred Go or project coding conventions. I also wasn't sure how best to include a test for the changes, other than by adding the test Excel file attached to this issue.

[xuri]

Thanks for your issue. Your fix is fine, I'll certainly accept that. Note that please do not add .xlsx file, test it after the picture_test.go#L221 like this:

diff --git a/picture_test.go b/picture_test.go
index aec0b5c..9da63f9 100644
--- a/picture_test.go
+++ b/picture_test.go
@@ -219,6 +219,19 @@ func TestGetPicture(t *testing.T) {
    cells, err := f.GetPictureCells("Sheet2")
    assert.NoError(t, err)
    assert.Equal(t, []string{"K16"}, cells)
+
+   // Try to get picture cells with absolute target path in the drawing relationship
+   rels, err := f.relsReader("xl/drawings/_rels/drawing2.xml.rels")
+   assert.NoError(t, err)
+   rels.Relationships[0].Target = "/xl/media/image2.jpeg"
+   cells, err = f.GetPictureCells("Sheet2")
+   assert.NoError(t, err)
+   assert.Equal(t, []string{"K16"}, cells)
+   // Try to get pictures with absolute target path in the drawing relationship
+   pics, err = f.GetPictures("Sheet2", "K16")
+   assert.NoError(t, err)
+   assert.Len(t, pics, 1)
+
    assert.NoError(t, f.Close())
 
    // Test get picture from none drawing worksheet