You have Multi line textbox on your InfoPath Form and after you published it, you noticed that your data is truncated on the library view and the field is published as Single Line of Text.
This is a known issue for Microsoft and looks like it is not yet fixed or won't be fixed. There is no solution to this, however, there are two workarounds which I can think of -
Option 1)
Create a Multi line Textbox and if not required, uncheck the richtext options and publish the form.
Option 2)
a) Publish the form library and if it is single line of text then create a Multi line text field on the form library.
b) Select Allow unlimited length while creating the column.
c) Go to the form publishing wizard, and on the field promotion, Select the field which you promoted, hit modify, and then map it with your new multiline field create on your library.
d) Now all your data is mapped to this new field, so you won't loose any record.
Cheers :) !
